前言:
知识点:1、进一步对输入格式的判断,设置字符串进行输入,对于产生的字符串的切割使用的函数,string.split()对于从不需要的字符串进行切割,难度中等,涉及到每一道题目
2、在上一点的基础上,对于每一种坐标的内容进行判断,判断是否为三点一线,两直线是否平行等内容,难度中等,其主要是对上一题的衍生,大部分是初高中的知识,需要判断的内容较多
3、在上一题的基础上,对于产生的三角形进行综合判断,难度较大,所涉及的知识点较少
4、正则表达式的判断,难度相对较小,对于上面几道题可以得到提升,缩短代码,其中很多的都是判断
5、设计类,对于类与类之间的关系进行设计与构造设计,一个人存在多个账号和多个卡号的设计
6、学会设计点与线的关系,通过输入点来构造线
7、点线面之间的构造,通过继承和多态的联系来设计出类与类之间的关系,向上造型,方法重写,实现不同的对象做同一件事的不同效果的展示。
8、构造容器类,需要掌握ArraryList容器类的用法,对于其中的内容进行删除与添加对象,在继承与多态的基础上再次构造
题目集:
(1):输入连个点的坐标,计算两点之间的距离
4个double类型的实数,两个点的x,y坐标,依次是x1、y1、x2、y2,两个点的坐标之间以空格分隔,每个点的x,y坐标以英文“,”分隔。例如:0,0 1,1或0.1,-0.3 +3.5,15.6。
若输入格式非法,输出"Wrong Format"。
若输入格式合法但坐标点的数量超过两个,输出“wrong number of points”。
计算所得的两点之间的距离。例如:1.4142135623730951
设计思路:需要对输入格式的输入进行控制,判断是否为Wrong Format或者是wrong number of points(应该是要设计字符串的,不能单独设计数字,一开始我也想过用数字,但是失败了,如果你们有更好的欢 迎评论区留言)
本题没有采用正则表达式,如果用正则表达式会简便很多,推荐大家去学习一下,确实很方便,几个字符解决了很多的事情,真的是yyds。
首先我们需要找到其中的间隔的位置,才能对格式进行判断
for(;i<getlength();i ++) { for(j = i;j<getlength();j++) { if(getData().charAt(j) =='+'||getData().charAt(j) == '-') add++; if(getData().charAt(j) == '.') dot++; if(getData().charAt(j) != '.'&&(getData().charAt(j) != '+'&&getData().charAt(j) != '-')&&!Character.isDigit(getData().charAt(j))) { i = j; num++;//表示找到了几组 break; //找到断点 } if(getData().charAt(j) == '.'&&!Character.isDigit(getData().charAt(j+1))) return 0;//格式错误 if((getData().charAt(j) == '+'||getData().charAt(j) == '-')&&j != i) return 0;//格式错误 if(getData().charAt(j) == '0'&&getData().charAt(j+1) == '0'&&j == i) return 0; } if(j == getlength()) break; if(add > 1||dot >1) return 0;//格式错误 add = 0; dot =0; if(num%2 == 0 &&getData().charAt(j) != ' ') return 0;//格式错误 if(num%2 != 0 &&getData().charAt(j) !=',') return 0;//格式错误 } if(j == getlength()&&num == 3) return 1;//表示格式正确,数据正确 if((num-3) %2 == 0&&num !=3) return 2;//表示数据错误 if(num %2 !=0 ) return 1;//表示格式错误 else return 0; }
对于是字符串的类型,需要对首先的“+-”这两个符号进行判断,可能是存在或者是不存在,同时每一组只能出现一次,对于需要里面每次产生的内容都进行计数,这是非常重要的,其实这个代码还是 可以的拓展的,将其中的内容进行稍微的更改一下,就可以实现代码的拓展,当然,这个除了使用正则表达式的以外,还可以使用其中string.split函数,这个会帮你自动切割,是非常方便的以后我们 会用到的
踩坑新得:相对于这个代码中,找位置,一开始就有很多的点需要找,因此,需要设计好,一开始,我就没有计数,这样就导致了出现了bug,比如说没有考虑到00,++,1.这样的数字,都是一时难以考虑完全 的,需要大家自己慢慢去设计。
改进建议:可以使用正则表达式去更改,这样会更好,推荐大家去尝试一下
(2)用户输入一组选项和数据,进行与直线有关的计算。选项包括:
1:输入两点坐标,计算斜率,若线条垂直于X轴,输出"Slope does not exist"。
2:输入三个点坐标,输出第一个点与另外两点连线的垂直距离。
3:输入三个点坐标,判断三个点是否在一条线上,输出true或者false。
4:输入四个点坐标,判断前两个点所构成的直线与后两点构成的直线是否平行,输出true或者false.
5:输入四个点坐标,计算输出前两个点所构成的直线与后两点构成的直线的交点坐标,x、y坐标之间以英文分隔",",并输出交叉点是否在两条线段之内(不含四个端点)的判断结果(true/false),判断结果与坐标之间以一个英文空格分隔。若两条线平行,没有交叉点,则输出"is parallel lines,have no intersection point"。
基本格式:选项+":"+坐标x+","+坐标y+" "+坐标x+","+坐标y。
例如:1:0,0 1,1
如果不符合基本格式,输出"Wrong Format"。
如果符合基本格式,但输入点的数量不符合要求,输出"wrong number of points"。
不论哪个选项,如果格式、点数量都符合要求,但构成任一条线的两个点坐标重合,输出"points coincide",
设计思路:这一题是对上一题的衍生,其中很多的代码时直接可以复制粘贴过来使用的,不需要很多的设计,但是还是其中还有很多的需要判断三点共线的等等,推荐大家可以先布局,想好思路和算法,这样可 以节省很多的时间,推荐大家上网查找一些公式,这里很多都是要判断,斜率是否存在,这是比较麻烦的
以下是源码(确实写的很不好,但是可以实现):
import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner in = new Scanner(System.in); String s = ""; char chance = 0; int mothod = 0; scanner scan = new scanner(); scan.scan();//先输入 chance = scan.getFirstchar(); if(scan.getData().charAt(0) > '5' || scan.getData().charAt(0) < '1') { System.out.println("Wrong Format"); System.exit(0); } if(chance == '1') { mothod = scan.j(); if(mothod == 0) System.out.println("Wrong Format"); if(mothod == 1) { scan.get(); if(scan.getX1() == scan.getX2()&&scan.getY1() != scan.getY2()) System.out.println("Slope does not exist"); else if(scan.getX1() == scan.getX2()&&scan.getY1() == scan.getY2()) System.out.println("points coincide"); else { System.out.println((scan.getY1()-scan.getY2())/(scan.getX1()-scan.getX2())); } } if(mothod == 2) System.out.println("wrong number of points"); } /*=======================================================*/ else if(chance == '2') { mothod = scan.j(); if(mothod == 0) System.out.println("Wrong Format"); if(mothod == 1) { scan.get(); if(scan.getX2() == scan.getX3()&&scan.getY2() == scan.getY3()) System.out.println("points coincide"); else if(scan.getX2() == scan.getX3()&&scan.getY2() != scan.getY3()) { if(scan.getX1() == scan.getX2()) System.out.println("0.0"); else if(scan.getX1() != scan.getX2()) System.out.println(Math.abs(scan.getX1()-scan.getX2())); } else { double k1 = (scan.getY1()-scan.getY2())/(scan.getX1()-scan.getX2()); double k2 = (scan.getY1()-scan.getY3())/(scan.getX1()-scan.getX3()); if(k1 != k2) { if(scan.getX2() != scan.getX3()) { double k = (scan.getY2()-scan.getY3())/(scan.getX2()-scan.getX3()); double feizi = Math.abs(k*scan.getX1()-scan.getY1()-k*scan.getX2()+scan.getY2()); double feimu = Math.sqrt(k*k+1); double d = feizi/feimu; System.out.println(d); } else if(scan.getX2() == scan.getX3()) { double d = Math.abs(scan.getX1()-scan.getX2()); System.out.println(d); } } if(k1 == k2) System.out.println("0.0"); } } if(mothod == 2) System.out.println("wrong number of points"); } /*==================================================*/ else if(chance == '3') { mothod = scan.j(); if(mothod == 0) System.out.println("Wrong Format"); if(mothod == 1) { scan.get(); if(scan.getX2() == scan.getX3()&&scan.getY2() == scan.getY3()) System.out.println("points coincide"); else if(scan.getX2() == scan.getX3()&&scan.getX1() == scan.getX3()) System.out.println("true"); else if(scan.getX2() == scan.getX3()&&scan.getX1() != scan.getX3()) System.out.println("false"); else { double k1 = (scan.getY1()-scan.getY2())/(scan.getX1()-scan.getX2()); double k2 = (scan.getY1()-scan.getY3())/(scan.getX1()-scan.getX3()); if(k1 == k2) System.out.println("true"); if(k1 != k2) System.out.println("false"); } } if(mothod == 2) System.out.println("wrong number of points"); } /*================================================*/ else if(chance == '4') { mothod = scan.j(); if(mothod == 0) System.out.println("Wrong Format"); if(mothod == 1) { scan.get(); if(scan.getX1() == scan.getX2()&&scan.getY1() == scan.getY2()) System.out.println("points coincide"); else if(scan.getX3() == scan.getX4()&&scan.getY3() == scan.getY4()) System.out.println("points coincide"); else if(scan.getX1() == scan.getX2()&&scan.getY1() != scan.getY2()&&scan.getX3() == scan.getX4()&&scan.getY3() != scan.getY4()) System.out.println("true"); else if(scan.getX1() == scan.getX2()&&scan.getY1() != scan.getY2()&&scan.getX3() != scan.getX4()) System.out.println("false"); else if(scan.getX1() != scan.getX2()&&scan.getX3() == scan.getX4()&&scan.getY3() != scan.getY4()) System.out.println("false"); else { double k1 = (scan.getY1()-scan.getY2())/(scan.getX1()-scan.getX2()); double k2 = (scan.getY3()-scan.getY4())/(scan.getX3()-scan.getX4()); if(k1 == k2) System.out.println("true"); if(k1 != k2) System.out.println("false"); } } if(mothod == 2) System.out.println("wrong number of points"); } /*====================================================*/ else if(chance == '5') { mothod = scan.j(); if(mothod == 0) System.out.println("Wrong Format"); if(mothod == 1) { scan.get(); if(scan.getX1() == scan.getX2()&&scan.getY1() == scan.getY2()) System.out.println("points coincide"); else if(scan.getX3() == scan.getX4()&&scan.getY3() == scan.getY4()) System.out.println("points coincide"); else if(scan.getX1() == scan.getX2()&&scan.getY1() != scan.getY2()&&scan.getX3() == scan.getX4()&&scan.getY3() != scan.getY4()) System.out.println("is parallel lines,have no intersection point"); /*一条在一条不存在*/else if(scan.getX1() == scan.getX2()&&scan.getY1() != scan.getY2()&&scan.getX3() != scan.getX4()) { double k2 = (scan.getY3()-scan.getY4())/(scan.getX3()-scan.getX4()); double y = k2*scan.getX1()-k2*scan.getX3()+scan.getY3(); float x = (float) scan.getX1(); System.out.print(x+","+(float)y); if((y - scan.getY1())*(y-scan.getY2()) <0||(scan.getX1() - scan.getX3())*(scan.getX1()-scan.getX4()) <0) System.out.println(" true"); else System.out.println(" false"); } else if(scan.getX1() != scan.getX2()&&scan.getX3() == scan.getX4()&&scan.getY3() != scan.getY4()) { double k2 = (scan.getY1()-scan.getY2())/(scan.getX1()-scan.getX2()); double y = k2*scan.getX3()-k2*scan.getX1()+scan.getY1(); float x = (float) scan.getX3(); System.out.print(scan.getX3()+","+(float)y); if((scan.getX3() - scan.getX1())*(scan.getX3()-scan.getX2()) <0||(y - scan.getY3())*(y-scan.getY4()) <0) System.out.println(" true"); else System.out.println(" false"); } else { double k1 = (scan.getY1()-scan.getY2())/(scan.getX1()-scan.getX2()); double k2 = (scan.getY3()-scan.getY4())/(scan.getX3()-scan.getX4()); if(k1 == k2) { System.out.println("is parallel lines,have no intersection point"); } if(k1 != k2) { double b1 = -k1*scan.getX1()+scan.getY1(); double b2 = -k2*scan.getX3()+scan.getY3(); double x = (b2-b1)/(k1-k2); double y = k1*x-k1*scan.getX1()+scan.getY1(); System.out.print((float)x+","+(float)y); if((x - scan.getX1())*(x-scan.getX2()) <0||(x - scan.getX3())*(x-scan.getX4()) <0) System.out.println(" true"); else System.out.println(" false"); } } } if(mothod == 2) System.out.println("wrong number of points"); } }//方法 }//类 class scanner {//输入一组字符串 private int L = 0; private String data = ""; private int pos [] = new int [100]; private double x1; private double y1; private double x2; private double y2; private double x3; private double y3; private double x4; private double y4; public scanner() { super(); // TODO 自动生成的构造函数存根 } public void scan() { Scanner in = new Scanner(System.in); data = in.nextLine(); L=data.length(); } public int getlength() { return L; } public String getData() { return data; } public char getFirstchar() { return data.charAt(0); } public double getX1() { return x1; } public void setX1(double x1) { this.x1 = x1; } public double getY1() { return y1; } public void setY1(double y1) { this.y1 = y1; } public double getX2() { return x2; } public void setX2(double x2) { this.x2 = x2; } public double getY2() { return y2; } public void setY2(double y2) { this.y2 = y2; } public double getX3() { return x3; } public void setX3(double x3) { this.x3 = x3; } public double getY3() { return y3; } public void setY3(double y3) { this.y3 = y3; } public double getX4() { return x4; } public void setX4(double x4) { this.x4 = x4; } public double getY4() { return y4; } public void setY4(double y4) { this.y4 = y4; } public int j() { int j = 0,i = 2; int add = 0,dot = 0,num = 0; if(getData().charAt(0) =='1') { if(getData().charAt(1) != ':') return 0;//格式错误 for(;i<getlength();i ++) { for(j = i;j<getlength();j++) { if(getData().charAt(j) =='+'||getData().charAt(j) == '-') add++; if(getData().charAt(j) == '.') dot++; if(getData().charAt(j) != '.'&&(getData().charAt(j) != '+'&&getData().charAt(j) != '-')&&!Character.isDigit(getData().charAt(j))) { i = j; pos[num] = j; num++;//表示找到了几组 break; //找到断点 } if(getData().charAt(j) == '.'&&!Character.isDigit(getData().charAt(j+1))) return 0;//格式错误 if((getData().charAt(j) == '+'||getData().charAt(j) == '-')&&j != i) return 0;//格式错误 if(getData().charAt(j) == '0'&&j == i&&j+1<getlength()) { if(Character.isDigit(getData().charAt(j+1))) return 0; } } if(j == getlength()) break; if(add > 1||dot >1) return 0;//格式错误 add = 0; dot =0; if(num%2 == 0 &&getData().charAt(j) != ' ') return 0;//格式错误 if(num%2 != 0 &&getData().charAt(j) !=',') return 0;//格式错误 } if(j == getlength()&&num == 3) return 1;//表示格式正确,数据正确 else if(i == getlength()&&!Character.isDigit(getData().charAt(getlength()-1))) return 0; else if((num-3) %2 == 0&&num !=3) return 2;//表示数据错误 else if(num %2 !=0 ) return 0;//表示格式错误 else return 0; } else if(getData().charAt(0) =='2'||getData().charAt(0)=='3') { if(getData().charAt(1) != ':') return 0;//格式错误 for(;i<getlength();i ++) { for(j = i;j<getlength();j++) { if(getData().charAt(j) =='+'||getData().charAt(j) == '-') add++; if(getData().charAt(j) == '.') dot++; if(getData().charAt(j) != '.'&&(getData().charAt(j) != '+'&&getData().charAt(j) != '-')&&!Character.isDigit(getData().charAt(j))) { i = j; pos[num] = j; num++;//表示找到了几组 break; //找到断点 } if(getData().charAt(j) == '.'&&!Character.isDigit(getData().charAt(j+1))) return 0;//格式错误 if((getData().charAt(j) == '+'||getData().charAt(j) == '-')&&j != i) return 0;//格式错误 if(getData().charAt(j) == '0'&&j == i&&j+1<getlength()) { if(Character.isDigit(getData().charAt(j+1))) return 0; } } if(j == getlength()) break; if(add > 1||dot >1) return 0;//格式错误 add = 0; dot =0; if(num%2 == 0 &&getData().charAt(j) != ' ') return 0;//格式错误 if(num%2 != 0 &&getData().charAt(j) !=',') return 0;//格式错误 } if(j == getlength()&&num == 5) return 1;//表示格式正确,数据正确 else if(i == getlength()&&!Character.isDigit(getData().charAt(getlength()-1))) return 0; else if((num-3) %2 == 0&&num !=5) return 2;//表示数据错误 else if(num %2 !=0 ) return 0;//表示格式错误 else return 0; } else if(getData().charAt(0) =='4'||getData().charAt(0)=='5') { if(getData().charAt(1) != ':') return 0;//格式错误 for(;i<getlength();i ++) { for(j = i;j<getlength();j++) { if(getData().charAt(j) =='+'||getData().charAt(j) == '-') add++; if(getData().charAt(j) == '.') dot++; if(getData().charAt(j) != '.'&&(getData().charAt(j) != '+'&&getData().charAt(j) != '-')&&!Character.isDigit(getData().charAt(j))) { i = j; pos[num] = j; num++;//表示找到了几组 break; //找到断点 } if(getData().charAt(j) == '.'&&!Character.isDigit(getData().charAt(j+1))) return 0;//格式错误 if((getData().charAt(j) == '+'||getData().charAt(j) == '-')&&j != i) return 0;//格式错误 if(getData().charAt(j) == '0'&&j == i&&j+1<getlength()) { if(Character.isDigit(getData().charAt(j+1))) return 0; } } if(j == getlength()) break; if(add > 1||dot >1) return 0;//格式错误 add = 0; dot =0; if(num%2 == 0 &&getData().charAt(j) != ' ') return 0;//格式错误 if(num%2 != 0 &&getData().charAt(j) !=',') return 0;//格式错误 } if(j == getlength()&&num == 7) return 1;//表示格式正确,数据正确 else if(i == getlength()&&!Character.isDigit(getData().charAt(getlength()-1))) return 0; else if((num-3) %2 == 0&&num !=7) return 2;//表示数据错误 else if(num %2 !=0 ) return 0;//表示格式错误 else return 0; } else return 0; }//方法的括号 public void get() { String stringx1 =""; String stringy1 =""; String stringx2 =""; String stringy2 =""; String stringx3 =""; String stringy3 =""; String stringx4 =""; String stringy4 =""; if(getData().charAt(0)=='1') { stringx1 = getData().substring(2,pos[0]); stringy1 = getData().substring(pos[0]+1,pos[1]); stringx2 = getData().substring(pos[1]+1,pos[2]); stringy2 = getData().substring(pos[2]+1,getlength()); x1 = Double.valueOf(stringx1.toString());//将字符串转化为数字 y1 = Double.valueOf(stringy1.toString());//将字符串转化为数字 x2 = Double.valueOf(stringx2.toString());//将字符串转化为数字 y2 = Double.valueOf(stringy2.toString());//将字符串转化为数字 } else if(getData().charAt(0)=='2'||getData().charAt(0)=='3') { stringx1 = getData().substring(2,pos[0]); stringy1 = getData().substring(pos[0]+1,pos[1]); stringx2 = getData().substring(pos[1]+1,pos[2]); stringy2 = getData().substring(pos[2]+1,pos[3]); stringx3 = getData().substring(pos[3]+1,pos[4]); stringy3 = getData().substring(pos[4]+1,getlength()); x1 = Double.valueOf(stringx1.toString());//将字符串转化为数字 y1 = Double.valueOf(stringy1.toString());//将字符串转化为数字 x2 = Double.valueOf(stringx2.toString());//将字符串转化为数字 y2 = Double.valueOf(stringy2.toString());//将字符串转化为数字 x3 = Double.valueOf(stringx3.toString());//将字符串转化为数字 y3 = Double.valueOf(stringy3.toString());//将字符串转化为数字 } else if(getData().charAt(0)=='4'||getData().charAt(0)=='5') { stringx1 = getData().substring(2,pos[0]); stringy1 = getData().substring(pos[0]+1,pos[1]); stringx2 = getData().substring(pos[1]+1,pos[2]); stringy2 = getData().substring(pos[2]+1,pos[3]); stringx3 = getData().substring(pos[3]+1,pos[4]); stringy3 = getData().substring(pos[4]+1,pos[5]); stringx4 = getData().substring(pos[5]+1,pos[6]); stringy4 = getData().substring(pos[6]+1,getlength()); x1 = Double.valueOf(stringx1.toString());//将字符串转化为数字 y1 = Double.valueOf(stringy1.toString());//将字符串转化为数字 x2 = Double.valueOf(stringx2.toString());//将字符串转化为数字 y2 = Double.valueOf(stringy2.toString());//将字符串转化为数字 x3 = Double.valueOf(stringx3.toString());//将字符串转化为数字 y3 = Double.valueOf(stringy3.toString());//将字符串转化为数字 x4 = Double.valueOf(stringx4.toString());//将字符串转化为数字 y4 = Double.valueOf(stringy4.toString());//将字符串转化为数字 } } }//类的括号View Code
其中的stringy1 = getData().substring(pos[0]+1,pos[1]);,这个时一个可以将其中的单独需要的内容提取出来,是比较方便的函数,同时我们还需要将其中的数字类型的字符出转换成double类型的数 字就需要用到一个函数Double.isvalueof(),这就可以将其中的内容,转换成Double类型的的数字
踩坑心得:其实在上面的设计思路中,我们就已经谈论到了,因为斜率不存在的问题,导致了我后面判断的时候写的很复杂,都是一直在讨论,强力推荐的大家好好的去构思一下,这个题目构思是非常重要的, 在写之前,一个单独的一点一点的将每一部分测试一下,就是比较好的方法,我再=在这里是吃了比较大的亏。
改进建议:这里面,改进的话,推荐大家采用一些叉乘的公式,这样就不用那么复杂的去讨论斜率存在,或者是不存在的问题,还不溶于出错,代码的行数比较少,特别好用,在写了这些题目后,才发现,真的 是,要想代码写的少,公式就要找的好,金玉良言。
设计ATM仿真系统,具体要求参见作业说明。
OO作业8-1题目说明.pdf
每一行输入一次业务操作,可以输入多行,最终以字符#终止。具体每种业务操作输入格式如下:
卡号 密码 ATM机编号 金额
(由一个或多个空格分隔),卡号
①输入错误处理
Sorry,this card does not exist.
。Sorry,the ATM's id is wrong.
。Sorry,your password is wrong.
。Sorry,your account balance is insufficient.
。Sorry,cross-bank withdrawal is not supported.
。②取款业务输出
输出共两行,格式分别为:
[用户姓名]在[银行名称]的[ATM编号]上取款¥[金额]
当前余额为¥[金额]
其中,[]说明括起来的部分为输出属性或变量,金额均保留两位小数。
③存款业务输出
输出共两行,格式分别为:
[用户姓名]在[银行名称]的[ATM编号]上存款¥[金额]
当前余额为¥[金额]
其中,[]说明括起来的部分为输出属性或变量,金额均保留两位小数。
④查询余额业务输出
¥[金额]
金额保留两位小数
设计思路:首先按照题目要求,构造出想要的类,对于每一个类,之间的方法,需要进行构思,对于一开始就没有设计好的好,产生了很多的重复代码,以至于代码长度会特别长,代码质量是不良的,所以我推 荐大家仅仅攻参考,这是像我这样学过c语言的人,比较难以摆脱的内容,需要慢慢向面向对象的方向进行走一走,设计时候,可以对于每个人的账号为一个类,采用继承的方式,每个人能的卡都继 承于同一个类,能够节省很多的重复的代码,实现代码的复用会好很多,而不是采用以每一个人来做一个类,我采用人的设计,导致后来产生了很多的问题
以下是源码(走了很多的弯路):
import java.text.DecimalFormat; import java.util.Scanner; public class Main { public static void main(String[] args) { // TODO 自动生成的方法存根 operation op = new operation(); op.operate(); } } class operation { datayang yang = new datayang(); dataguo guo = new dataguo(); datazhang zhang = new datazhang(); datawei wei = new datawei(); show sho = new show(); private String [] qq = new String [100]; private String q = ""; private int []size = new int [100]; public void operate() { Scanner in = new Scanner(System.in); int i = -1,j = -1; int times = 0; int []casee = new int [100]; while(true) { i++; qq[i] = in.nextLine(); size[i] = qq[i].length(); if(qq[i].equals("#")) break; }//先存储 while(true) { j++; if(qq[j].matches("^[0-9]{19}[ ]{1,}[0-9]{8}[ ]{1,}[0-9][0-9][ ]{1,}-?([1-9]\\d*.\\d*|0.\\d[1-9]\\d*)")) { casee[j] = 1;times++; } else if(qq[j].matches("^[0-9]{19}")) { casee[j] = 2;times++; } else if(qq[j].equals("#")) break; else break; }//再正则判断 for(j = 0;j < times;j++) {//j表示正确的数目 if(casee[j] == 1) { // String x1 = qq[j].substring(0,19);//卡号 // String x2 = qq[j].substring(20,28);//密码 // String x3 = qq[j].substring(29,31);//机器 // String x4 = qq[j].substring(32,size[j]);//钱 String []x = qq[j].split("\\s+"); double money = Double.valueOf(x[3]); String a = String.format("%.2f", money); money = Double.valueOf(a); if(x[0].equals(yang.getCard1())||x[0].equals(yang.getCard2())) { if(x[1].equals("88888888")) { if(x[2].equals("01")||x[2].equals("02")||x[2].equals("03")||x[2].equals("04")) { if(money<=yang.getLastMoney1()) { yang.setLastMoney1(yang.getLastMoney1()-money); sho.showData1_1(yang, x[2], money); } else System.out.println("Sorry,your account balance is insufficient."); } else if(x[2].equals("05")||x[2].equals("06")) System.out.println("Sorry,cross-bank withdrawal is not supported."); else System.out.println("Sorry,the ATM's id is wrong."); } else System.out.println("Sorry,your password is wrong."); } /*------------------------------*/ else if(x[0].equals(yang.getCard3())) { if(x[1].equals("88888888")) { if(x[2].equals("01")||x[2].equals("02")||x[2].equals("03")||x[2].equals("04")) { if(money<=yang.getLastMoney2()) { yang.setLastMoney2(yang.getLastMoney2()-money); sho.showData1_3(yang, x[2], money); } else System.out.println("Sorry,your account balance is insufficient."); } else if(x[2].equals("05")||x[2].equals("06")) System.out.println("Sorry,cross-bank withdrawal is not supported."); else System.out.println("Sorry,the ATM's id is wrong."); } else System.out.println("Sorry,your password is wrong."); } /*-----------------------------*/ else if(x[0].equals(guo.getCard2())) { if(x[1].equals("88888888")) { if(x[2].equals("01")||x[2].equals("02")||x[2].equals("03")||x[2].equals("04")) { if(money<=guo.getLastMoney()) { guo.setLastMoney(guo.getLastMoney()-money); sho.showData2_1(guo, x[2], money); } else System.out.println("Sorry,your account balance is insufficient."); } else if(x[2].equals("05")||x[2].equals("06")) System.out.println("Sorry,cross-bank withdrawal is not supported."); else System.out.println("Sorry,the ATM's id is wrong."); } else System.out.println("Sorry,your password is wrong."); } /*-------------------------------*/ else if(x[0].equals(zhang.getCard1())) { if(x[1].equals("88888888")) { if(x[2].equals("05")||x[2].equals("06")) { if(money<=zhang.getLastMoney1()) { zhang.setLastMoney1(zhang.getLastMoney1()-money); sho.showData3_1(zhang, x[2], money); } else System.out.println("Sorry,your account balance is insufficient."); } else if(x[2].equals("01")||x[2].equals("02")||x[2].equals("03")||x[2].equals("04")) System.out.println("Sorry,cross-bank withdrawal is not supported."); else System.out.println("Sorry,the ATM's id is wrong."); } else System.out.println("Sorry,your password is wrong."); } /*------------------------------*/ else if(x[0].equals(zhang.getCard2())) { if(x[1].equals("88888888")) { if(x[2].equals("05")||x[2].equals("06")) { if(money<=zhang.getLastMoney2()) { zhang.setLastMoney2(zhang.getLastMoney2()-money); sho.showData3_3(zhang, x[2], money); } else System.out.println("Sorry,your account balance is insufficient."); } else if(x[2].equals("01")||x[2].equals("02")||x[2].equals("03")||x[2].equals("04")) System.out.println("Sorry,cross-bank withdrawal is not supported."); else System.out.println("Sorry,the ATM's id is wrong."); } else System.out.println("Sorry,your password is wrong."); } /*-----------------------*/ else if(x[0].equals(zhang.getCard3())||x[0].equals(zhang.getCard4())) { if(x[1].equals("88888888")) { if(x[2].equals("05")||x[2].equals("06")) { if(money<=zhang.getLastMoney3()) { zhang.setLastMoney3(zhang.getLastMoney3()-money); sho.showData3_5(zhang, x[2], money); } else System.out.println("Sorry,your account balance is insufficient."); } else if(x[2].equals("01")||x[2].equals("02")||x[2].equals("03")||x[2].equals("04")) System.out.println("Sorry,cross-bank withdrawal is not supported."); else System.out.println("Sorry,the ATM's id is wrong."); } else System.out.println("Sorry,your password is wrong."); } /*----------------------------*/ else if(x[0].equals(wei.getCard1())) { if(x[1].equals("88888888")) { if(x[2].equals("05")||x[2].equals("06")) { if(money<=wei.getLastMoney1()) { wei.setLastMoney1(wei.getLastMoney1()-money); sho.showData4_1(wei, x[2], money); } else System.out.println("Sorry,your account balance is insufficient."); } else if(x[2].equals("01")||x[2].equals("02")||x[2].equals("03")||x[2].equals("04")) System.out.println("Sorry,cross-bank withdrawal is not supported."); else System.out.println("Sorry,the ATM's id is wrong."); } else System.out.println("Sorry,your password is wrong."); } /*------------------------------*/ else if(x[0].equals(wei.getCard2())) { if(x[1].equals("88888888")) { if(x[2].equals("05")||x[2].equals("06")) { if(money<wei.getLastMoney2()) { wei.setLastMoney2(wei.getLastMoney2()-money); sho.showData4_3(wei, x[2], money); } else System.out.println("Sorry,your account balance is insufficient."); } else if(x[2].equals("01")||x[2].equals("02")||x[2].equals("03")||x[2].equals("04")) System.out.println("Sorry,cross-bank withdrawal is not supported."); else System.out.println("Sorry,the ATM's id is wrong."); } else System.out.println("Sorry,your password is wrong."); } else System.out.println("Sorry,this card does not exist."); } if(casee[j] == 2) { String x1 = qq[j].substring(0,19);//卡号 if(x1.equals(yang.getCard1())||x1.equals(yang.getCard2())) sho.showData1_2(yang); else if(x1.equals(yang.getCard3())) sho.showData1_4(yang); else if(x1.equals(guo.getCard2())) sho.showData2_2(guo); else if(x1.equals(zhang.getCard1())) sho.showData3_2(zhang); else if(x1.equals(zhang.getCard2())) sho.showData3_4(zhang); else if(x1.equals(zhang.getCard3())||x1.equals(zhang.getCard4())) sho.showData3_6(zhang); else if(x1.equals(wei.getCard1())) sho.showData4_2(wei); else if(x1.equals(wei.getCard2())) sho.showData4_4(wei); else System.out.println("Sorry,this card does not exist."); } } } } class show { public void showData1_1(datayang information,String machine,double num){ if(num>0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上取款¥"+new DecimalFormat("0.00").format(num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney1())); } else if(num<0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上存款¥"+new DecimalFormat("0.00").format(-num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney1())); } } public void showData1_2(datayang information){ System.out.println("¥"+new DecimalFormat("0.00").format(information.getLastMoney1())); } ////////////////// public void showData1_3(datayang information,String machine,double num){ if(num>0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上取款¥"+new DecimalFormat("0.00").format(num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney2())); } else if(num<0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上存款¥"+new DecimalFormat("0.00").format(-num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney2())); } } public void showData1_4(datayang information){ System.out.println("¥"+new DecimalFormat("0.00").format(information.getLastMoney2())); } /////////////////////// public void showData2_1(dataguo information,String machine,double num){ if(num>0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上取款¥"+new DecimalFormat("0.00").format(num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney())); } else if(num<0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上存款¥"+ new DecimalFormat("0.00").format(-num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney())); } } public void showData2_2(dataguo information){ System.out.println("¥"+new DecimalFormat("0.00").format(information.getLastMoney())); } /////////////////////// public void showData3_1(datazhang information,String machine,double num){ if(num>0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上取款¥"+new DecimalFormat("0.00").format(num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney1())); } else if(num<0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上存款¥"+new DecimalFormat("0.00").format(-num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney1())); } } public void showData3_2(datazhang information){ System.out.println("¥"+new DecimalFormat("0.00").format(information.getLastMoney1())); } /////////////////////// public void showData3_3(datazhang information,String machine,double num){ new DecimalFormat("0.00").format(num); new DecimalFormat("0.00").format(information.getLastMoney2()); if(num>0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上取款¥"+new DecimalFormat("0.00").format(num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney2())); } else if(num<0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上存款¥"+new DecimalFormat("0.00").format(-num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney2())); } } public void showData3_4(datazhang information){ System.out.println("¥"+new DecimalFormat("0.00").format(information.getLastMoney2())); } //////////////// public void showData3_5(datazhang information,String machine,double num){ if(num>0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上取款¥"+new DecimalFormat("0.00").format(num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney3())); } else if(num<0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上存款¥"+new DecimalFormat("0.00").format(-num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney3())); } } public void showData3_6(datazhang information){ System.out.println("¥"+new DecimalFormat("0.00").format(information.getLastMoney3())); } ////////////////////// public void showData4_1(datawei information,String machine,double num){ new DecimalFormat("0.00").format(num); new DecimalFormat("0.00").format(information.getLastMoney1()); if(num>0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上取款¥"+new DecimalFormat("0.00").format(num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney1())); } else if(num<0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上存款¥"+new DecimalFormat("0.00").format(-num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney1())); } } public void showData4_2(datawei information){ System.out.println("¥"+new DecimalFormat("0.00").format(information.getLastMoney1())); } ////////////////////// public void showData4_3(datawei information,String machine,double num){ new DecimalFormat("0.00").format(num); new DecimalFormat("0.00").format(information.getLastMoney2()); if(num>0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上取款¥"+new DecimalFormat("0.00").format(num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney2())); } else if(num<0) { System.out.println(information.getName()+"在"+information.getBank()+"的"+machine+"号ATM机上存款¥"+new DecimalFormat("0.00").format(-num)); System.out.println("当前余额为¥"+new DecimalFormat("0.00").format(information.getLastMoney2())); } } public void showData4_4(datawei information){ System.out.println("¥"+new DecimalFormat("0.00").format(information.getLastMoney2())); } } class datayang { private String name = "杨过"; private String bank = "中国建设银行"; private double lastMoney1 = 10000; private double lastMoney2 = 10000; private String bankCard1 = "3217000010041315709" ; private String bankCard2 = "3217000010041315709" ; private String card1 = "6217000010041315709"; private String card2 = "6217000010041315715"; private String card3 = "6217000010041315718"; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getBank() { return bank; } public void setBank(String bank) { this.bank = bank; } public double getLastMoney1() { return lastMoney1; } public void setLastMoney1(double lastMoney1) { this.lastMoney1 = lastMoney1; } public double getLastMoney2() { return lastMoney2; } public void setLastMoney2(double lastMoney2) { this.lastMoney2 = lastMoney2; } public String getBankCard1() { return bankCard1; } public void setBankCard1(String bankCard1) { this.bankCard1 = bankCard1; } public String getBankCard2() { return bankCard2; } public void setBankCard2(String bankCard2) { this.bankCard2 = bankCard2; } public String getCard1() { return card1; } public void setCard1(String card1) { this.card1 = card1; } public String getCard2() { return card2; } public void setCard2(String card2) { this.card2 = card2; } public String getCard3() { return card3; } public void setCard3(String card3) { this.card3 = card3; } } class dataguo { private String name= "郭靖"; private String bank = "中国建设银行"; private double lastMoney = 10000; private String bankCard = "3217000010051320007" ; private String card2 = "6217000010051320007"; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getBank() { return bank; } public void setBank(String bank) { this.bank = bank; } public double getLastMoney() { return lastMoney; } public void setLastMoney(double lastMoney) { this.lastMoney = lastMoney; } public String getBankCard() { return bankCard; } public void setBankCard(String bankCard) { this.bankCard = bankCard; } public String getCard2() { return card2; } public void setCard2(String card2) { this.card2 = card2; } } class datazhang { private String name = "张无忌"; private String bank = "中国工商银行"; private double lastMoney1 = 10000; private double lastMoney2 = 10000; private double lastMoney3 = 10000; private String bankCard1 = "3222081502001312389" ; private String bankCard2 = "3222081502001312390" ; private String bankCard3 = "3222081502001312399" ; private String card1 = "6222081502001312389"; private String card2 = "6222081502001312390"; private String card3 = "6222081502001312399"; private String card4 = "6222081502001312400"; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getBank() { return bank; } public void setBank(String bank) { this.bank = bank; } public double getLastMoney1() { return lastMoney1; } public void setLastMoney1(double lastMoney1) { this.lastMoney1 = lastMoney1; } public double getLastMoney2() { return lastMoney2; } public void setLastMoney2(double lastMoney2) { this.lastMoney2 = lastMoney2; } public double getLastMoney3() { return lastMoney3; } public void setLastMoney3(double lastMoney3) { this.lastMoney3 = lastMoney3; } public String getBankCard1() { return bankCard1; } public void setBankCard1(String bankCard1) { this.bankCard1 = bankCard1; } public String getBankCard2() { return bankCard2; } public void setBankCard2(String bankCard2) { this.bankCard2 = bankCard2; } public String getBankCard3() { return bankCard3; } public void setBankCard3(String bankCard3) { this.bankCard3 = bankCard3; } public String getCard1() { return card1; } public void setCard1(String card1) { this.card1 = card1; } public String getCard2() { return card2; } public void setCard2(String card2) { this.card2 = card2; } public String getCard3() { return card3; } public void setCard3(String card3) { this.card3 = card3; } public String getCard4() { return card4; } public void setCard4(String card4) { this.card4 = card4; } } class datawei { private String name = "韦小宝"; private String bank = "中国工商银行"; private double lastMoney1 = 10000; private double lastMoney2 = 10000; private String bankCard1 = "3222081502051320785" ; private String bankCard2 = "3222081502051320786" ; private String card1 = "6222081502051320785"; private String card2 = "6222081502051320786"; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getBank() { return bank; } public void setBank(String bank) { this.bank = bank; } public double getLastMoney1() { return lastMoney1; } public void setLastMoney1(double lastMoney1) { this.lastMoney1 = lastMoney1; } public double getLastMoney2() { return lastMoney2; } public void setLastMoney2(double lastMoney2) { this.lastMoney2 = lastMoney2; } public String getBankCard1() { return bankCard1; } public void setBankCard1(String bankCard1) { this.bankCard1 = bankCard1; } public String getBankCard2() { return bankCard2; } public void setBankCard2(String bankCard2) { this.bankCard2 = bankCard2; } public String getCard1() { return card1; } public void setCard1(String card1) { this.card1 = card1; } public String getCard2() { return card2; } public void setCard2(String card2) { this.card2 = card2; } }View Code
踩坑新得:从上述可以看出来,这个类图十分混乱,而且,每一个里面的内容字段特别多,里面设计非常不合理,不推荐大家使用,包括里面还有很多的重复代码,十分不好,希望大家能够先罗列出一些好的 计方案,再去施行,这样才是对滴,别直接动手,最后花费的时间还会更多,设计好了在以后,还可以把以前的代码,再次拿来使用,这是比较好的方向,对于我们这些初学者,还是先设计,因为, 我们学习的java就是面向对象的设计,类与类之间就是要解除耦合,这样才能够在以后方便拓展和复用。
改进方案:采用继承的方式,将其中的重复的类进行继承,比如说,其中的每一个人的账户很多的内容都是相同的,我们可以了解一些继承的内容,然后去对这些账户内容复用,能够大大减少代码的行数,实现 好的代码。
设计一个类表示平面直角坐标系上的点Point,私有属性分别为横坐标x与纵坐标y,数据类型均为实型数,除构造方法以及属性的getter与setter方法外,定义一个用于显示信息的方法display(),用来输出该坐标点的坐标信息,格式如下:(x,y)
,数值保留两位小数。为简化题目,其中,坐标点的取值范围设定为(0,200]
。若输入有误,系统则直接输出Wrong Format
设计一个类表示平面直角坐标系上的线Line,私有属性除了标识线段两端的点point1、point2外,还有一个字符串类型的color,用于表示该线段的颜色,同样,除构造方法以及属性的getter与setter方法外,定义一个用于计算该线段长度的方法getDistance(),还有一个用于显示信息的方法display(),用来输出线段的相关信息,输出格式如下:
``` The line's color is:颜色值 The line's begin point's Coordinate is: (x1,y1) The line's end point's Coordinate is: (x2,y2) The line's length is:长度值 ```
其中,所有数值均保留两位小数,建议可用String.format("%.2f", data)
方法。
设计思路:设计出一个Line类和Point类,其中,在Point类中进行输入,每次输入一个点,在Line类中创建两个Point的对象j,就可以实现,输入两个点,在每一个类中都存在独自的方法,比如说计算距离的 getDistance(),和disPlay()这样的方法,该题目相对于来说较为简单,比较好实现。
以下是源代码:
import java.util.Scanner; public class Main { public static void main(String[] args) { // TODO 自动生成的方法存根 Scanner in = new Scanner(System.in); double x1 = in.nextDouble(); double y1 = in.nextDouble(); double x2 = in.nextDouble(); double y2 = in.nextDouble(); String color = in.next(); if(x1 > 0&&x1 <= 200 &&y1 > 0&&y1 <= 200 &&x2 > 0&&x2 <= 200 &&y2 > 0&&y2 <= 200){ Point point1 = new Point(x1,y1); Point point2 = new Point(x2,y2); Line line = new Line(point1,point2,color); line.display(); } else System.out.println("Wrong Format"); } } class Line { private Point point1 = new Point(); private Point point2 = new Point(); private String color = ""; public Line() { super(); // TODO 自动生成的构造函数存根 } public Line(Point point1, Point point2, String color) { super(); this.point1 = point1; this.point2 = point2; this.color = color; } public Point getPoint1() { return point1; } public void setPoint1(Point point1) { this.point1 = point1; } public Point getPoint2() { return point2; } public void setPoint2(Point point2) { this.point2 = point2; } public String getColor() { return color; } public void setColor(String color) { this.color = color; } public double getDistance() { double distance = Math.sqrt(Math.pow(point1.getX() - point2.getX(),2) + Math.pow(point1.getY() - point2.getY(),2)); return distance; } public void display() { System.out.println("The line's color is:" + color); System.out.println("The line's begin point's Coordinate is:"); point1.display(); System.out.println("The line's end point's Coordinate is:"); point2.display(); System.out.printf("The line's length is:"); System.out.printf(String.format("%.2f", getDistance())); } } class Point { private double x = 0; private double y = 0; public Point() { super(); // TODO 自动生成的构造函数存根 } public Point(double x, double y) { super(); this.x = x; this.y = y; } public double getX() { return x; } public void setX(double x) { this.x = x; } public double getY() { return y; } public void setY(double y) { this.y = y; } public void display () { System.out.printf("("); System.out.printf(String.format("%.2f", x)); System.out.printf(","); System.out.printf(String.format("%.2f", y)); System.out.printf(")"); System.out.println(""); } }View Code
踩坑心得:不太清楚什么in.nextLine(),无法输入,一开始没有找到缺点,最后发现后改成了in.next(),就可以了,我也不知道是为什么,同时要对每一个点都要进行判断条件(0,200],一开始就没有太注意,导 致犯了很严重的错误,自己也没有发现,希望大家能够,在写代码的时候,考虑完全,别丢三落四,忘掉了很多的条件,导致自己都不知道自己错在哪里了。这也是程序员比较忌讳的东西。
在“点与线(类设计)”题目基础上,对题目的类设计进行重构,以实现继承与多态的技术性需求。
The Plane's color is:颜色
element = p1;//起点Point element.display(); element = p2;//终点Point element.display(); element = line;//线段 element.display(); element = plane;//面 element.display();
设计思路:按照类图的要求,我们只需要在上一题的代码上进行迭代,就可以了。增加了一个plane的面类,将前三个都继承与Element类,三者都继承了Element的display方法,并且都进行了重写,实现了多态
在输出的时候,要使用向上转型,实现多态,一个对象做同一件事的不同效果,多态特性。
以下是源代码:写的还好吧,可以看看。
import java.util.Scanner; public class Main { public static void main(String[] args) { // TODO 自动生成的方法存根 Scanner in = new Scanner(System.in); double x1 = in.nextDouble(); double y1 = in.nextDouble(); double x2 = in.nextDouble(); double y2 = in.nextDouble(); String color = in.next(); if(x1 > 0&&x1 <= 200 &&y1 > 0&&y1 <= 200 &&x2 > 0&&x2 <= 200 &&y2 > 0&&y2 <= 200) { Point point1 = new Point(x1,y1); Point point2 = new Point(x2,y2); Plane plane = new Plane(color); Line line = new Line(point1,point2,color); Element element; element = point1; element.display(); element = point2; element.display(); element = line; element.display(); element = plane; element.display(); } else System.out.println("Wrong Format"); } } class Line extends Element{ private Point point1 = new Point(); private Point point2 = new Point(); private String color = ""; public Line() { super(); // TODO 自动生成的构造函数存根 } public Line(Point point1, Point point2, String color) { super(); this.point1 = point1; this.point2 = point2; this.color = color; } public Point getPoint1() { return point1; } public void setPoint1(Point point1) { this.point1 = point1; } public Point getPoint2() { return point2; } public void setPoint2(Point point2) { this.point2 = point2; } public String getColor() { return color; } public void setColor(String color) { this.color = color; } public double getDistance() { double distance = Math.sqrt(Math.pow(point1.getX() - point2.getX(),2) + Math.pow(point1.getY() - point2.getY(),2)); return distance; } public void display() { System.out.println("The line's color is:" + color); System.out.println("The line's begin point's Coordinate is:"); point1.display(); System.out.println("The line's end point's Coordinate is:"); point2.display(); System.out.printf("The line's length is:"); System.out.println(String.format("%.2f", getDistance())); } } class Point extends Element{ private double x = 0; private double y = 0; public Point() { super(); // TODO 自动生成的构造函数存根 } public Point(double x, double y) { super(); this.x = x; this.y = y; } public double getX() { return x; } public void setX(double x) { this.x = x; } public double getY() { return y; } public void setY(double y) { this.y = y; } public void display () { System.out.printf("("); System.out.printf(String.format("%.2f", x)); System.out.printf(","); System.out.printf(String.format("%.2f", y)); System.out.printf(")"); System.out.println(""); } } abstract class Element { public abstract void display(); } class Plane extends Element{ private String color = ""; public Plane() { super(); // TODO 自动生成的构造函数存根 } public Plane(String color) { super(); this.color = color; } public String getColor() { return color; } public void setColor(String color) { this.color = color; } public void display() { System.out.printf("The Plane's color is:" + color); } }View Code
踩坑心得:说实话,这个题目,没什么坑,认真去写,多考虑以下,也就能够完成了。
在“点与线(继承与多态)”题目基础上,对题目的类设计进行重构,增加容器类保存点、线、面对象,并对该容器进行相应增、删、遍历操作。
ArrayList<Element>
类型的对象(若不了解泛型,可以不使用<Element>
)add()
方法及remove(int index)
方法,其功能分别为向容器中增加对象及删除第index - 1
(ArrayList中index>=0)个对象choice = input.nextInt(); while(choice != 0) { switch(choice) { case 1://insert Point object into list ... break; case 2://insert Line object into list ... break; case 3://insert Plane object into list ... break; case 4://delete index - 1 object from list int index = input.nextInt(); ... } choice = input.nextInt(); }输入结束后,按容器中的对象顺序分别调用每个对象的
display()
方法进行输出。
设计思路:在原有类设计的基础上,增加一个GeometryObject容器类,其属性为ArrayList<Element>类型的对象,其中里面设计出一个add和remove的方法,其实这个容器类,是java自带的比 较好用,可以多去了解一下,然后去使用一下,就可以实现
以下是源代码:
import java.util.Scanner; import java.util.ArrayList; public class Main { public static void main(String[] args) { // TODO 自动生成的方法存根 Scanner in = new Scanner(System.in); GeometryObject geometryObject = new GeometryObject(); int choice = in.nextInt(); while(choice != 0) { switch(choice) { case 1:{//insert Point object into list 输入“点”对象的x,y值 double x1 = in.nextDouble(); double y1 = in.nextDouble(); if(x1 > 0&&x1 <= 200 &&y1 > 0&&y1 <= 200 ) { Point point1 = new Point(x1,y1); geometryObject.add(point1); } else System.out.println("Wrong Format"); } break; case 2:{//insert Line object into list输入“线”对象两个端点的x,y值 double x1 = in.nextDouble(); double y1 = in.nextDouble(); double x2 = in.nextDouble(); double y2 = in.nextDouble(); if(x1 > 0&&x1 <= 200 &&y1 > 0&&y1 <= 200 &&x2 > 0&&x2 <= 200 &&y2 > 0&&y2 <= 200) { Point point1 = new Point(x1,y1); Point point2 = new Point(x2,y2); String color = in.next(); Line line = new Line(point1,point2,color); geometryObject.add(line); } else System.out.println("Wrong Format"); } break; case 3:{//insert Plane object into list输入“面”对象的颜色值 String color = in.next(); Plane plane = new Plane(color); geometryObject.add(plane); } break; case 4:{//delete index - 1 object from list输入要删除的对象位置(从1开始) ... int index = in.nextInt(); geometryObject.remove(index); } } choice = in.nextInt(); } for(Element e : geometryObject.getList()) { e.display(); } } } class Line extends Element{ private Point point1 = new Point(); private Point point2 = new Point(); private String color = ""; public Line() { super(); // TODO 自动生成的构造函数存根 } public Line(Point point1, Point point2, String color) { super(); this.point1 = point1; this.point2 = point2; this.color = color; } public Point getPoint1() { return point1; } public void setPoint1(Point point1) { this.point1 = point1; } public Point getPoint2() { return point2; } public void setPoint2(Point point2) { this.point2 = point2; } public String getColor() { return color; } public void setColor(String color) { this.color = color; } public double getDistance() { double distance = Math.sqrt(Math.pow(point1.getX() - point2.getX(),2) + Math.pow(point1.getY() - point2.getY(),2)); return distance; } public void display() { System.out.println("The line's color is:" + color); System.out.println("The line's begin point's Coordinate is:"); point1.display(); System.out.println("The line's end point's Coordinate is:"); point2.display(); System.out.printf("The line's length is:"); System.out.println(String.format("%.2f", getDistance())); } } class Point extends Element{ private double x = 0; private double y = 0; public Point() { super(); // TODO 自动生成的构造函数存根 } public Point(double x, double y) { super(); this.x = x; this.y = y; } public double getX() { return x; } public void setX(double x) { this.x = x; } public double getY() { return y; } public void setY(double y) { this.y = y; } public void display () { System.out.printf("("); System.out.printf(String.format("%.2f", x)); System.out.printf(","); System.out.printf(String.format("%.2f", y)); System.out.printf(")"); System.out.println(""); } } abstract class Element { public abstract void display(); } class Plane extends Element{ private String color = ""; public Plane() { super(); // TODO 自动生成的构造函数存根 } public Plane(String color) { super(); this.color = color; } public String getColor() { return color; } public void setColor(String color) { this.color = color; } public void display() { System.out.println("The Plane's color is:" + color); } } class GeometryObject { private ArrayList <Element> list = new ArrayList<>(); public GeometryObject() { super(); // TODO 自动生成的构造函数存根 } public void add(Element element) { list.add(element); } public void remove(int index) { if(index > 0&& index < list.size()) list.remove(index - 1); } public ArrayList<Element> getList() { return list; } }View Code
踩坑心得:对于ArrayList这个类,我掌握的不好,导致在这个上面花了很多的时间,最终还是没有怎么实现好,这是很麻烦的事情,希望大家能够先去将Array List这个类了解是什么,如何使用,会使用后,就能 够很熟练的掌握这些内容了
java链表的实现:单向链表和双向链表
很多的都是需要大家自己去理解的,难以讲解清楚:
package test47; public interface DoubleListInterface<E> { public boolean isEmpty(); public int getSize(); public E get(int index); public void remove(int index); public void add(int index, E theElement); public void add(E element); public void printList(); public E getFirst(); public E getLast(); } package test47; public class LList<E> implements DoubleListInterface<E> { private Node<E> head;// 头结点(非第一个节点),当前节点,尾节点 private Node<E> curr; private Node<E> tail; private int size = 0; public LList() { super(); // TODO Auto-generated constructor stub head = new Node<E>(); head.setNext(null); head.setPrevious(null); curr = tail = null; this.size = 0; } @Override public boolean isEmpty() { // TODO Auto-generated method stub return this.size == 0; } @Override public int getSize() { // TODO Auto-generated method stub return this.size; } @Override public E get(int index) {//查找 // TODO Auto-generated method stub if(index < 1 || index > this.size) { return null; } curr = head; for(int i = 0; i < index; i ++) { curr = curr.getNext(); } return curr.getData(); } @Override public void remove(int index) { // TODO Auto-generated method stub if(index < 1 || index > this.size) { return ; } curr = head; if(index == 1) { curr.getNext().setPrevious(head); curr = head.getNext(); head.setNext(curr.getNext()); }else {//找到第index - 1个节点赋给curr for(int i = 1;i < index; i++) { curr = curr.getNext(); } curr.getNext().getNext().setPrevious(curr); curr.setNext(curr.getNext().getNext()); } if(index == this.size) {//如果删除的是最后一个节点 tail = curr; } this.size --;//整个链表的节点数量-1 } @Override public void add(int index, E theElement) {//指定位置添加 // TODO Auto-generated method stub if(index < 1 || index > this.size + 1) { return ; } Node<E> curr = new Node<>(); curr.setData(theElement); curr.setNext(null); curr.setPrevious(null); if(this.size == 0) { head.setNext(curr); tail = curr; curr.setPrevious(head); }else if(index == this.size + 1) { this.tail.setNext(curr); curr.setPrevious(tail); tail = curr; }else { Node<E> tempNode = head; for(int i = 1; i < index;i++) { tempNode = tempNode.getNext(); } curr.setNext(tempNode.getNext()); tempNode.getNext().setPrevious(curr); curr.setPrevious(tempNode); tempNode.setNext(curr); // for(int i = size ; i >= index ; i-- ) { // tail.getFront() = // } } this.size ++; } @Override public void add(E element) { // TODO Auto-generated method stub this.add(this.size + 1,element); } @Override public void printList() { // TODO Auto-generated method stub curr = head.getNext(); for(int i = 1; i <= this.size;i ++) { System.out.print(curr.getData() + " "); curr = curr.getNext(); } System.out.println(""); } public E getLast() { if(this.size != 0) { return tail.getData(); } return null; } public E getFirst() { if(this.size != 0) { return head.getNext().getData(); } return null; }package test47; public class Main { public static void main(String[] args) { // TODO Auto-generated method stub LList<Integer> list = new LList<>(); list.add(2); list.add(4); list.add(6); list.add(8); list.printList(); list.remove(3); list.printList(); list.add(2,100); list.printList(); System.out.println(list.get(4)); } } package test47; //Node public class Node<E> { private Node<E> previous; private E data; private Node<E> next; public Node() { } public Node(E data, Node<E> next,Node<E> previous) { super(); this.data = data; this.next = next; this.previous = previous; } public E getData() { return data; } public void setData(E data) { this.data = data; } public Node<E> getNext() { return next; } public void setNext(Node<E> next) { this.next = next; } public Node<E> getPrevious() { return previous; } public void setPrevious(Node<E> previous) { this.previous = previous; } } }双向链表
package asdfnz; public class main { public static void main(String[] args) { // TODO 自动生成的方法存根 List<String> list = new List<String>(); list.add("1"); list.add("2"); list.add("3"); list.add("4"); list.add("5"); // list.printList(); list.remove(1); list.add(3,"asd"); list.printList(); } } interface LinearListInterface<E> { public boolean isEmpty(); public int size(); public E get(int index); public void remove(int index); public void add(int index, E theElement); public void add(E element); public void printList(); } //LinkedList class class LList<E>{ private Node<E> head,curr,tail; private int size; public int getSize() { return size; } public void setSize(int size) { this.size = size; } } //Node class Node<E>{ private E o; private Node<E> next; public E getO() { return o; } public void setO(E o) { this.o = o; } public Node<E> getNext() { return next; } public void setNext(Node<E> next) { this.next = next; } } class List<E> implements LinearListInterface<E>{ private Node<E> head = new Node<E>(); private Node<E> curr = new Node<E>(); private Node<E> tail = new Node<E>(); int length = 0; @Override public boolean isEmpty() { if(curr.getO() == null) return true; else return false; } @Override public int size() { return 0; } @Override public E get(int index) { if(curr.getO() != null ) return curr.getO(); else return null; } @Override public void remove(int index) {//表示删除 Node<E> p = new Node<E>(); int i = 1; if(head != tail) { for(i = 1,p = head ;p != tail ; i++ , p = p.getNext()) { if(i == index &&index == 1&&p.getNext() != null) { head = p.getNext(); break; } else if(i == index-1 &&index != 1&&p.getNext().getNext() != null){ p.setNext(p.getNext().getNext()); break; } else if(i == index-1 &&index != 1&&p.getNext().getNext() == null){ tail = p; break; } } } else { head = null; } } @Override public void add(int index, E theElement) {//表示指定位置增加 //需要跳转节点 Node p = new Node(); Node q = new Node(); q.setO(theElement); int i = 1; if(head != tail) for(i = 1,p = head ; p!=tail ; i++ , p = p.getNext()) { if(index == 1&&i == index) { head = q; break; } else if(index != 1&& i == index-1) { q.setNext(p.getNext()); p.setNext(q); break; } else if(i == index-1 &&index != 1&&p.getNext().getNext() == null) { tail.setNext(q); q.setNext(null); break; } } } @Override public void add(E element) {//从最后面增加 Node curr1= new Node(); curr1.setO(element); curr = curr1; if(head.getO()== null) { head = curr; tail = curr; head.setNext(null); } else { tail.setNext(curr); tail = curr; tail.setNext(null); } } @Override public void printList() { Node<E> p = new Node<E>(); if(head != tail) { for( p = head;p != tail ;p = p.getNext() ) { System.out.println(p.getO()); } System.out.println(tail.getO()); } else if(head == tail) System.out.println(head.getO()); } }单向链表
说实话,下面这道题是最难的一道题,困扰了我很久,最后都没有完成,大家可以先浅看一下题目:
用户输入一组选项和数据,进行与四边形有关的计算。
以下四边形顶点的坐标要求按顺序依次输入,连续输入的两个顶点是相邻顶点,第一个和最后一个输入的顶点相邻。
选项包括:
1:输入四个点坐标,判断是否是四边形、平行四边形,判断结果输出true/false,结果之间以一个英文空格符分隔。
2:输入四个点坐标,判断是否是菱形、矩形、正方形,判断结果输出true/false,结果之间以一个英文空格符分隔。 若四个点坐标无法构成四边形,输出"not a quadrilateral"
3:输入四个点坐标,判断是凹四边形(false)还是凸四边形(true),输出四边形周长、面积,结果之间以一个英文空格符分隔。 若四个点坐标无法构成四边形,输出"not a quadrilateral"
4:输入六个点坐标,前两个点构成一条直线,后四个点构成一个四边形或三角形,输出直线与四边形(也可能是三角形)相交的交点数量。如果交点有两个,再按面积从小到大输出四边形(或三角形)被直线分割成两部分的面积(不换行)。若直线与四边形或三角形的一条边线重合,输出"The line is coincide with one of the lines"。若后四个点不符合四边形或三角形的输入,输出"not a quadrilateral or triangle"。
后四个点构成三角形的情况:假设三角形一条边上两个端点分别是x、y,边线中间有一点z,另一顶点s:
1)符合要求的输入:顶点重复或者z与xy都相邻,如x x y s、x z y s、x y x s、s x y y。此时去除冗余点,保留一个x、一个y。
2) 不符合要求的输入:z 不与xy都相邻,如z x y s、x z s y、x s z y
5:输入五个点坐标,输出第一个是否在后四个点所构成的四边形(限定为凸四边形,不考虑凹四边形)或三角形(判定方法见选项4)的内部(若是四边形输出in the quadrilateral/outof the quadrilateral,若是三角形输出in the triangle/outof the triangle)。如果点在多边形的某条边上,输出"on the triangle或者on the quadrilateral"。若后四个点不符合四边形或三角形,输出"not a quadrilateral or triangle"
设计思路:对于一开始的那几道题,我的其中的很多的东西在这里是无法使用,因为设计的不好,代码比较长,包括判断,这个代码长度限制在了800行左右,难以实现,所以很多的代码,我都重 写了,并且能够用方法的全部使用了。设计思路是需要先用正则表达式判断是不是合法的输入,以及是不点重合,或者其中的点的数量是不是正确,这些都需要判断,其中,使用正则 表达式,只用了我几行代码,就完成了判断,这是一个比较好的方法:以下是判断的代码
String [] a = x.split(" "); int i = 0; if(a[0].matches("^[1-6][:]((-|[+])?(([1-9]+[0-9]{0,})|[0]))(\\.\\d+)?[,]((-|[+])?(([1-9]+[0-9]{0,})|[0]))(\\.\\d+)?") == true) { for(i = 1 ; i < a.length ; i++) { if(a[i].matches("^((-|[+])?(([1-9]+[0-9]{0,})|[0]))(\\.\\d+)?[,]((-|[+])?(([1-9]+[0-9]{0,})|[0]))(\\.\\d+)?") == false) { System.out.print("Wrong Format"); System.exit(0); } } if(i == a.length&& i != 1) return i;//返回几个点] else if(i == 1) { System.out.print("wrong number of points"); System.exit(0); } } else System.out.print("Wrong Format");//存在一个超出范围的没有设置 return 0; }View Code
短短10行实现了多种类型的判断,同时也要使用循环判断的方式这样可以节省很多时间,还有提取数字的方法,也进行了修改,也从原来的单一方法变成了循环提取,这样又可以节省很多,将判断四 边形平行,四边形菱形,矩形正方形等,都单独设置一个方法,这样方便,以后调用,四边形的判断比较复杂,推荐在网上找好公式,不要自己轻易的去判断,很容易遗漏一些特殊的值,判断完是否 是四边形之后可以再次,在基础上判断是否是平行四边形,之后,在平行四边形的基础上,再次叠加判断菱形,矩形,正方形等,这是我们,编写代码之前必须做好的工作,判断是凸四边形还是凹四 边形的时候其实比较好判断,采用的方法对了,也就容易了,我们可以采用面积法,进行切割,这样可以很快的实现。嗯,进行到输入六个点坐标的时候就比较复杂了,新药判断是否是三角形或者构 成的点,是否是四边形,其中有很多是按顺序输入的,导致他可能会扭转在一起,这是一个比较难以判断的点,希望大家能够注意到,然后进行切割,判断面积,并计算出面积,输出面积,最后一点 是判断一个点是否在三角形或者四边形内,这还是可以采用面积法,这是比较容易的一次判断里面我们还需要一系列方法,比如说求两条直线的交点坐标,判断三点是否共线,这些都是需要我们单独 设立方法比较好的
以下是不完全代码:可以参考一下,大部分的内容还是实现了的。
import java.util.Scanner; public class Main { public static void main(String[] args) { // TODO 自动生成的方法存根 Scanner in = new Scanner(System.in); String x = in.nextLine(); Judge judg = new Judge(x); int chance = judg.judge(); double[] xy = new double[12]; xy = judg.getNum(chance); if(x.charAt(0) == '1'){//第一种情况 if(chance == 4) { if(judg.quadrabgle(xy) ==1) System.out.printf("true "); else System.out.printf("false "); if(judg.parallelogram(xy))System.out.println("true"); else System.out.println("false"); } else System.out.println("wrong number of points"); } if(x.charAt(0) == '2') { if(chance == 4) { if(judg.quadrabgle(xy) == 0) { System.out.print("not a quadrilateral"); System.exit(0); } if(judg.quadrabgle(xy) == 2) { System.out.println("points coincide"); System.exit(0); } if(judg.rhombus(xy)) System.out.print("true "); else System.out.print("false "); if(judg.rectangle(xy)) System.out.print("true "); else System.out.print("false "); if(judg.square(xy)) System.out.println("true"); else System.out.println("false"); } else System.out.println("wrong number of points"); } if(x.charAt(0) == '3') { if(chance == 4) { if(judg.quadrabgle(xy) == 0) { System.out.print("not a quadrilateral"); System.exit(0); } double s1 = 0,s2 = 0,s3 = 0,s4 = 0; s1 = Math.abs(xy[2]*xy[5]+xy[4]*xy[1]+xy[0]*xy[3]-xy[2]*xy[1]-xy[0]*xy[5]-xy[4]*xy[3]);//123 s2 = Math.abs(xy[2]*xy[7]+xy[6]*xy[1]+xy[0]*xy[3]-xy[2]*xy[1]-xy[0]*xy[7]-xy[6]*xy[3]);//124 s3 = Math.abs(xy[2]*xy[5]+xy[4]*xy[7]+xy[6]*xy[3]-xy[2]*xy[7]-xy[6]*xy[5]-xy[4]*xy[3]);//234 s4 = Math.abs(xy[4]*xy[7]+xy[6]*xy[1]+xy[0]*xy[5]-xy[4]*xy[1]-xy[0]*xy[7]-xy[6]*xy[5]);//134 double c = Math.sqrt(Math.pow(xy[0] - xy[2],2) + Math.pow(xy[1] - xy[3],2)) + Math.sqrt(Math.pow(xy[2] - xy[4],2) + Math.pow(xy[3] - xy[5],2)) + Math.sqrt(Math.pow(xy[4] - xy[6],2) + Math.pow(xy[5] - xy[7],2)) + Math.sqrt(Math.pow(xy[0] - xy[6],2) + Math.pow(xy[1] - xy[7],2)); if(s1+s4 == s2+s3) { System.out.print("true "); System.out.print(Math.round(c*1000)/1000.0); System.out.print(" "); System.out.print(Math.round((s1 + s4)/2*1000)/1000.0); } else{ System.out.print("false "); if(s1 + s4 < s2 + s3) { System.out.print(Math.round(c*1000)/1000.0); System.out.print(" "); System.out.print(Math.round((s1 + s4)/2*1000)/1000.0 ); } else { System.out.print(Math.round(c*1000)/1000.0); System.out.print(" "); System.out.print(Math.round((s2 + s3)/2*1000)/1000.0); } } } else System.out.println("Wrong Format"); } if(x.charAt(0) == '5') { if(chance == 5) { judg.case5(xy); } else System.out.println("Wrong Format"); } if(x.charAt(0) == '4') { if(chance == 6) { judg.difficult(xy); } else System.out.println("Wrong Format"); } } } class Judge { private String x; private double [] num = new double[10]; public Judge(String x) { super(); this.x = x; } public int judge() { String [] a = x.split(" "); int i = 0; if(a[0].matches("^[1-6][:]((-|[+])?(([1-9]+[0-9]{0,})|[0]))(\\.\\d+)?[,]((-|[+])?(([1-9]+[0-9]{0,})|[0]))(\\.\\d+)?") == true) { for(i = 1 ; i < a.length ; i++) { if(a[i].matches("^((-|[+])?(([1-9]+[0-9]{0,})|[0]))(\\.\\d+)?[,]((-|[+])?(([1-9]+[0-9]{0,})|[0]))(\\.\\d+)?") == false) { System.out.print("Wrong Format"); System.exit(0); } } if(i == a.length&& i != 1) return i;//返回几个点] else if(i == 1) { System.out.print("wrong number of points"); System.exit(0); } } else System.out.print("Wrong Format");//存在一个超出范围的没有设置 return 0; } public double[] getNum(int dot) { String [] stringPlace = new String [12]; double [] place = new double [12]; int pos1 = 0; int pos2 = 0; String [] a = x.split(" ");//1:123,25; for(int i = 1; ;i ++) { if(x.charAt(i) == ',') pos1 = i; if(x.charAt(i) == ' ') { pos2 = i;break; } } stringPlace[0] = a[0].substring(2,pos1); stringPlace[1] = a[0].substring(pos1+1,pos2); for(int i = 1,j = 2;i < dot ;i ++,j = j + 2) { String [] temp = a[i].split(","); stringPlace[j] = temp[0]; stringPlace[j+1] = temp[1]; } for(int i = 0 ;i < dot*2; i++) { place[i] = Double.valueOf(stringPlace[i]); } return place; } public double pointX(double x1,double y1,double x2,double y2,double x3,double y3,double x4,double y4) { double x = -((x3-x4)*(x2*y1-x1*y2)-(x1-x2)*(x4*y3-x3*y4))/((y3-y4)*(x1-x2)-(y1-y2)*(x3-x4)); return x; } public double pointY(double x1,double y1,double x2,double y2,double x3,double y3,double x4,double y4) {//求焦点坐标 double y = -((y3-y4)*(y2*x1-y1*x2)-(y1-y2)*(y4*x3-y3*x4))/((x3-x4)*(y1-y2)-(x1-x2)*(y3-y4)); return y; } public double getArea(double x1,double y1,double x2,double y2,double x3,double y3) {//已知三点求面积 double area = Math.abs(x2*y3 + x3*y1 + x1*y2 - x2*y1 - x1*y3 - x3*y2); return area/2; } public double sumArea(double x1,double y1,double x2,double y2,double x3,double y3,double x4,double y4) {//求四边形面积 double s1 = getArea(x1,y1,x2,y2,x3,y3); double s2 = getArea(x1,y1,x3,y3,x4,y4); double s3 = getArea(x1,y1,x2,y2,x4,y4); double s4 = getArea(x2,y2,x3,y3,x4,y4); if(s1 + s2 <= s3 +s4) return s1 + s2; else { return s3 + s4; } } public boolean judgejudge(double X,double Y,double x1,double y1,double x2,double y2) { if((X-x1)*(X-x2) < 0&&(Y-y1)*(Y-y2) <= 0 ||(X-x1)*(X-x2) <= 0&&(Y-y1)*(Y-y2) < 0) return true; else return false; } public int triangle(double xy[]) { if(quadrabgle(xy) == 0||quadrabgle(xy) == 2) {//首先不是四边形 double d1 = getArea(xy[0],xy[1],xy[2],xy[3],xy[4],xy[5]);//123 double d2 = getArea(xy[0],xy[1],xy[2],xy[3],xy[6],xy[7]);//124 double d3 = getArea(xy[2],xy[3],xy[4],xy[5],xy[6],xy[7]);//234 double d4 = getArea(xy[0],xy[1],xy[4],xy[5],xy[6],xy[7]);//134 if(d1 == 0&&d2 !=0 && (judgejudge(xy[2],xy[3],xy[0],xy[1],xy[3],xy[4])||(xy[0] == xy[2]&&xy[1] == xy[3]||xy[4] == xy[2]&&xy[5] == xy[3]))){ return 1; } else if(d3 == 0&&d2 !=0 && (judgejudge(xy[4],xy[5],xy[2],xy[3],xy[6],xy[7])||(xy[2] == xy[4]&&xy[3] == xy[5]||xy[6] == xy[4]&&xy[7] == xy[5]))){ return 2; } else if(d4 == 0&&d1 !=0 && (judgejudge(xy[6],xy[7],xy[0],xy[1],xy[4],xy[5])||(xy[0] == xy[6]&&xy[1] == xy[7]||xy[4] == xy[6]&&xy[5] == xy[7]))){ return 3; } else if(d2 == 0&&d4 !=0 && (judgejudge(xy[0],xy[1],xy[2],xy[3],xy[6],xy[7])||(xy[2] == xy[0]&&xy[3] == xy[1]||xy[6] == xy[0]&&xy[7] == xy[1]))){ return 4; } else return 0; } else return 0; } public int quadrabgle(double xy[]) {//判断四边形 double x1 = pointX(xy[0],xy[1],xy[2],xy[3],xy[4],xy[5],xy[6],xy[7]); double y1 = pointY(xy[0],xy[1],xy[2],xy[3],xy[4],xy[5],xy[6],xy[7]); double x2 = pointX(xy[0],xy[1],xy[6],xy[7],xy[2],xy[3],xy[4],xy[5]); double y2 = pointY(xy[0],xy[1],xy[6],xy[7],xy[2],xy[3],xy[4],xy[5]); if((xy[0] == xy[2]&&xy[1] == xy[3])||(xy[2] == xy[4]&&xy[3] == xy[5])||(xy[4] == xy[6]&&xy[5] == xy[7])||(xy[0] == xy[6]&&xy[1] == xy[7])) { return 2; } else if(getArea(xy[0],xy[1],xy[2],xy[3],xy[4],xy[5]) == 0 ||getArea(xy[0],xy[1],xy[2],xy[3],xy[6],xy[7]) == 0 || getArea(xy[6],xy[7],xy[2],xy[3],xy[4],xy[5]) == 0 ||getArea(xy[0],xy[1],xy[3],xy[4],xy[6],xy[7]) == 0 ) return 0; else if(getArea(xy[4],xy[5],xy[0],xy[1],xy[2],xy[3]) == getArea(xy[6],xy[7],xy[0],xy[1],xy[2],xy[3])&&getArea(xy[2],xy[3],xy[0],xy[1],xy[6],xy[7]) != getArea(xy[4],xy[5],xy[0],xy[1],xy[6],xy[7])&& (judgejudge(x2,y2,xy[2],xy[3],xy[4],xy[5])==true||judgejudge(x1,y1,xy[0],xy[1],xy[6],xy[7])==true)) //12和34平行 return 0; else if(getArea(xy[4],xy[5],xy[0],xy[1],xy[2],xy[3]) != getArea(xy[6],xy[7],xy[0],xy[1],xy[2],xy[3])&&getArea(xy[2],xy[3],xy[0],xy[1],xy[6],xy[7]) == getArea(xy[4],xy[5],xy[0],xy[1],xy[6],xy[7])&& (judgejudge(x2,y2,xy[2],xy[3],xy[4],xy[5])==true&&judgejudge(x1,y1,xy[0],xy[1],xy[6],xy[7])==true)) //14和23平行 return 0; else if(getArea(xy[4],xy[5],xy[0],xy[1],xy[2],xy[3]) == getArea(xy[6],xy[7],xy[0],xy[1],xy[2],xy[3])&&getArea(xy[2],xy[3],xy[0],xy[1],xy[6],xy[7]) == getArea(xy[4],xy[5],xy[0],xy[1],xy[6],xy[7])) { double x = pointX(xy[0],xy[1],xy[6],xy[7],xy[2],xy[3],xy[4],xy[5]); double y = pointY(xy[0],xy[1],xy[6],xy[7],xy[2],xy[3],xy[4],xy[5]); if(judgejudge(x,y,xy[0],xy[1],xy[6],xy[7])==true) return 0; else return 1; } else if((judgejudge(x1,y1,xy[0],xy[1],xy[2],xy[3])==false&&judgejudge(x1,y1,xy[4],xy[5],xy[6],xy[7])==false)||(judgejudge(x2,y2,xy[2],xy[3],xy[4],xy[5])==false&&judgejudge(x1,y1,xy[0],xy[1],xy[6],xy[7])==false)) { double d1 = getArea(xy[0],xy[1],xy[2],xy[3],xy[4],xy[5]);//123 double d2 = getArea(xy[0],xy[1],xy[2],xy[3],xy[6],xy[7]);//124 double d3 = getArea(xy[2],xy[3],xy[4],xy[5],xy[6],xy[7]);//234 double d4 = getArea(xy[0],xy[1],xy[4],xy[5],xy[6],xy[7]);//134 if(d1 != 0&&d2 != 0&&d3 != 0&&d4 != 0) return 1; else return 0; } else return 0; } public boolean parallelogram(double xy[]) {//判断平行四边形 if(quadrabgle(xy) == 1 ) { double a = Math.pow((xy[0]-xy[2]),2)+Math.pow((xy[1]-xy[3]),2); double b = Math.pow((xy[2]-xy[4]),2)+Math.pow((xy[3]-xy[5]),2); double c = Math.pow((xy[4]-xy[6]),2)+Math.pow((xy[5]-xy[7]),2); double d = Math.pow((xy[6]-xy[0]),2)+Math.pow((xy[7]-xy[1]),2); if(a == c&&b == d) return true; else return false; } else return false; } public boolean rhombus(double xy[]) {//判断是菱形 if(parallelogram(xy) == true) { double a = Math.pow((xy[0]-xy[2]),2)+Math.pow((xy[1]-xy[3]),2); double b = Math.pow((xy[2]-xy[4]),2)+Math.pow((xy[3]-xy[5]),2); double c = Math.pow((xy[4]-xy[6]),2)+Math.pow((xy[5]-xy[7]),2); double d = Math.pow((xy[6]-xy[0]),2)+Math.pow((xy[7]-xy[1]),2); if(a == b&&a == d) return true; else return false; } else return false; } public boolean rectangle(double xy[]) {//判断是矩形 if(parallelogram(xy) == true) { double oppo1 = Math.pow((xy[0]-xy[4]),2)+Math.pow((xy[1]-xy[5]),2); double oppo2 = Math.pow((xy[2]-xy[6]),2)+Math.pow((xy[3]-xy[7]),2); if(oppo1 == oppo2) return true; else return false; } else return false; } public boolean square(double xy[]) {//判断是正方形 if(rectangle(xy) == true) { double a = Math.pow((xy[0]-xy[2]),2)+Math.pow((xy[1]-xy[3]),2); double b = Math.pow((xy[2]-xy[4]),2)+Math.pow((xy[3]-xy[5]),2); if(a == b) return true; else return false; } else return false; } public boolean highAndShort(double xy[]) {//判断凸凹四边形:true是凸的,false是凹的 if(quadrabgle(xy) == 1 ) { double s1 = 0,s2 = 0,s3 = 0,s4 = 0; s1 = Math.abs(xy[2]*xy[5]+xy[4]*xy[1]+xy[0]*xy[3]-xy[2]*xy[1]-xy[0]*xy[5]-xy[4]*xy[3]);//123 s2 = Math.abs(xy[2]*xy[7]+xy[6]*xy[1]+xy[0]*xy[3]-xy[2]*xy[1]-xy[0]*xy[7]-xy[6]*xy[3]);//124 s3 = Math.abs(xy[2]*xy[5]+xy[4]*xy[7]+xy[6]*xy[3]-xy[2]*xy[7]-xy[6]*xy[5]-xy[4]*xy[3]);//234 s4 = Math.abs(xy[4]*xy[7]+xy[6]*xy[1]+xy[0]*xy[5]-xy[4]*xy[1]-xy[0]*xy[7]-xy[6]*xy[5]);//134 if(s1+s4 == s2+s3) return true; else return false; } else return false; } public void case5(double XY[]) { double xy[] = {XY[2],XY[3],XY[4],XY[5],XY[6],XY[7],XY[8],XY[9]}; if(quadrabgle(xy) == 1) { double d1 = getArea(XY[0],XY[1],xy[0],xy[1],xy[2],xy[3]); double d2 = getArea(XY[0],XY[1],xy[2],xy[3],xy[4],xy[5]); double d3 = getArea(XY[0],XY[1],xy[4],xy[5],xy[6],xy[7]); double d4 = getArea(XY[0],XY[1],xy[6],xy[7],xy[0],xy[1]); double s = sumArea(xy[0],xy[1],xy[2],xy[3],xy[4],xy[5],xy[6],xy[7]); if((d1 == 0 ||d2 == 0 ||d3 == 0 ||d4 == 0 )&&(s == d1 + d2 + d3 + d4)) System.out.println("on the quadrilateral"); else if(s == d1 + d2 + d3 + d4) System.out.println("in the quadrilateral"); else System.out.println("outof the quadrilateral"); } else if(triangle(xy) == 1) { double d1 = getArea(XY[0],XY[1],xy[0],xy[1],xy[4],xy[5]); double d2 = getArea(XY[0],XY[1],xy[0],xy[1],xy[6],xy[7]); double d3 = getArea(XY[0],XY[1],xy[4],xy[5],xy[6],xy[7]); double s = getArea(xy[0],xy[1],xy[4],xy[5],xy[6],xy[7]); if((d1 == 0 ||d2 == 0 ||d3 == 0 )&&s == d1 + d2 + d3 ) System.out.println("on the triangle"); else if(s == d1 + d2 + d3 ) System.out.println("in the triangle"); else System.out.println("outof the triangle"); } else if(triangle(xy) == 2) { double d1 = getArea(XY[0],XY[1],xy[0],xy[1],xy[2],xy[3]); double d2 = getArea(XY[0],XY[1],xy[2],xy[3],xy[6],xy[7]); double d3 = getArea(XY[0],XY[1],xy[0],xy[1],xy[6],xy[7]); double s = getArea(xy[0],xy[1],xy[2],xy[3],xy[6],xy[7]); if((d1 == 0 ||d2 == 0 ||d3 == 0 )&&s == d1 + d2 + d3 ) System.out.println("on the triangle"); else if(s == d1 + d2 + d3 ) System.out.println("in the triangle"); else System.out.println("outof the triangle"); } else if(triangle(xy) == 3) { double d1 = getArea(XY[0],XY[1],xy[0],xy[1],xy[2],xy[3]); double d2 = getArea(XY[0],XY[1],xy[0],xy[1],xy[4],xy[5]); double d3 = getArea(XY[0],XY[1],xy[2],xy[3],xy[4],xy[5]); double s = getArea(xy[0],xy[1],xy[2],xy[3],xy[4],xy[5]); if((d1 == 0 ||d2 == 0 ||d3 == 0 )&&s == d1 + d2 + d3 ) System.out.println("on the triangle"); else if(s == d1 + d2 + d3 ) System.out.println("in the triangle"); else System.out.println("outof the triangle"); } else if(triangle(xy) == 4) { double d1 = getArea(XY[0],XY[1],xy[2],xy[3],xy[6],xy[7]); double d2 = getArea(XY[0],XY[1],xy[2],xy[3],xy[4],xy[5]); double d3 = getArea(XY[0],XY[1],xy[4],xy[5],xy[6],xy[7]); double s = getArea(xy[2],xy[3],xy[4],xy[5],xy[6],xy[7]); if((d1 == 0 ||d2 == 0 ||d3 == 0 )&&s == d1 + d2 + d3 ) System.out.println("on the triangle"); else if(s == d1 + d2 + d3 ) System.out.println("in the triangle"); else System.out.println("outof the triangle"); } else System.out.println("not a quadrilateral or triangle"); } public void difficult(double XY[]) {//这里面有6个点,需要将前两个排除 double [] xy ={XY[4],XY[5],XY[6],XY[7],XY[8],XY[9],XY[10],XY[11]};//可能存在问题 if(XY[0] == XY[3]&&XY[1] == XY[4]) {//前面两个点重合 System.out.println("points coincide"); System.exit(0); } if(quadrabgle(xy) == 1) {//如果是四边形 //点到直线的距离,存在四条 double s = sumArea(xy[0],xy[1],xy[2],xy[3],xy[4],xy[5],xy[6],xy[7]);//求四边形面积 double d1 = getArea(XY[0],XY[1],XY[2],XY[3],xy[0],xy[1]);//1 double d2 = getArea(XY[0],XY[1],XY[2],XY[3],xy[2],xy[3]);//2 double d3 = getArea(XY[0],XY[1],XY[2],XY[3],xy[4],xy[5]);//3 double d4 = getArea(XY[0],XY[1],XY[2],XY[3],xy[6],xy[7]);//4 int num12 = 0,num23 = 0,num34 = 0,num41 = 0,sum = 0; //求焦点坐标 double X1 = pointX(XY[0],XY[1],XY[2],XY[3],xy[0],xy[1],xy[2],xy[3]); double Y1 = pointY(XY[0],XY[1],XY[2],XY[3],xy[0],xy[1],xy[2],xy[3]);//12 double X2 = pointX(XY[0],XY[1],XY[2],XY[3],xy[2],xy[3],xy[4],xy[5]); double Y2 = pointY(XY[0],XY[1],XY[2],XY[3],xy[2],xy[3],xy[4],xy[5]);//23 double X3 = pointX(XY[0],XY[1],XY[2],XY[3],xy[4],xy[5],xy[6],xy[7]); double Y3 = pointY(XY[0],XY[1],XY[2],XY[3],xy[4],xy[5],xy[6],xy[7]);//34 double X4 = pointX(XY[0],XY[1],XY[2],XY[3],xy[6],xy[7],xy[0],xy[1]); double Y4 = pointY(XY[0],XY[1],XY[2],XY[3],xy[6],xy[7],xy[0],xy[1]);//41 //判断是否在线段内 if(judgejudge(X1,Y1,xy[0],xy[1],xy[2],xy[3]))//判断有几个焦点 num12++;//与12 if(judgejudge(X2,Y2,xy[2],xy[3],xy[4],xy[5])) num23++;//23 if(judgejudge(X3,Y3,xy[4],xy[5],xy[6],xy[7])) num34++;//34 if(judgejudge(X4,Y4,xy[6],xy[7],xy[0],xy[1])) num41++;//41 sum = num12 + num23 + num34 + num41; if((d1 == 0&&d4 == 0)||(d1 == 0&&d2 == 0)||(d2 == 0&&d3 == 0)||(d3 == 0&&d4 == 0)) {//表示两条线重合了 System.out.println("The line is coincide with one of the lines"); System.exit(0); } else if(d1 != 0&&d2 != 0&&d3 != 0&&d4 != 0) {//表示与顶点一个都不相交 System.out.println(sum); if(num12 == 1&&num23 == 1&&num41 == 0&&num41 == 0) { double s1 = getArea(X1,Y1,X2,Y2,xy[2],xy[3]); System.out.print(s1 + " "); System.out.println(s - s1); System.exit(0); } else if(num23 == 1&&num34 == 1&&num41 == 0&& num12 == 0) { double s1 = getArea(X2,Y2,X3,Y3,xy[4],xy[5]); System.out.print(s1 + " "); System.out.println(s - s1); System.exit(0); } else if(num34 == 1&&num41 == 1&& num12 == 0&& num23 == 0) { double s1 = getArea(X3,Y3,X4,Y4,xy[6],xy[7]); System.out.print(s1 + " "); System.out.println(s - s1); System.exit(0); } else if(num41 == 1&&num12 == 1&& num23 == 0&& num34 == 0) { double s1 = getArea(X4,Y4,X1,Y1,xy[0],xy[1]); System.out.print(s1 + " "); System.out.println(s - s1); System.exit(0); } else if(num12 == 1&&num34 == 1&&num23 == 0&&num41 == 0) {//形成两个四边形 double s1 = sumArea(X1,Y1,X3,Y3,xy[0],xy[1],xy[6],xy[7]); double s2 = sumArea(X1,Y1,X3,Y3,xy[2],xy[3],xy[4],xy[5]); if(s1 <= s2) { System.out.print(s1 + " "); System.out.println(s - s1); } else { System.out.print(s2 + " "); System.out.println(s - s2); } } else if(num23 == 1&&num41 == 1&&num12 == 0&&num34 == 0) { double s1 = sumArea(X2,Y2,X4,Y4,xy[0],xy[1],xy[2],xy[3]); double s2 = sumArea(X2,Y2,X4,Y4,xy[4],xy[5],xy[6],xy[7]); if(s1 <= s2) { System.out.print(s1 + " "); System.out.println(s - s1); } else { System.out.print(s2 + " "); System.out.println(s - s2); } } } else if(d1 == 0&&d3 == 0||d2 == 0&&d4 == 0) {//存在连个端点相交,就是对角线相交 double s1 = 0,s2 = 0,s3 = 0,s4 = 0; s1 = Math.abs(xy[2]*xy[5]+xy[4]*xy[1]+xy[0]*xy[3]-xy[2]*xy[1]-xy[0]*xy[5]-xy[4]*xy[3]);//123 s2 = Math.abs(xy[2]*xy[7]+xy[6]*xy[1]+xy[0]*xy[3]-xy[2]*xy[1]-xy[0]*xy[7]-xy[6]*xy[3]);//124 s3 = Math.abs(xy[2]*xy[5]+xy[4]*xy[7]+xy[6]*xy[3]-xy[2]*xy[7]-xy[6]*xy[5]-xy[4]*xy[3]);//234 s4 = Math.abs(xy[4]*xy[7]+xy[6]*xy[1]+xy[0]*xy[5]-xy[4]*xy[1]-xy[0]*xy[7]-xy[6]*xy[5]);//134 System.out.println("2"); if(highAndShort(xy)) { System.out.print(s/2+" "); System.out.println(s/2); } else if(!highAndShort(xy)&&d1 == 0&&d3 == 0) { if(s1+s4 > s2+s3) { System.out.print(s/2+" "); System.out.println(s/2); } } else if(!highAndShort(xy)&&d2 == 0&&d4 == 0) { if(s1+s4 < s2+s3) { System.out.print(s/2+" "); System.out.println(s/2); } } } //只存在一个端点 else if(d1 == 0&&d2 != 0&&d3 != 0&&d4 != 0) {//并且要与四边形有两个交点 System.out.println(sum); if(num23 == 1 && num12 == 0&& num34 ==0 &&num41 == 0) { double s1 = getArea(xy[0],xy[1],xy[2],xy[3],X2,Y2); double s2 = s - s1; if(s1 <= s2) { System.out.print(s1 + " "); System.out.println(s - s1); } else { System.out.print(s2 + " "); System.out.println(s - s2); } } if(num34 == 1&&num12 == 0&& num23 ==0 &&num41 == 0) { double s1 = getArea(xy[0],xy[1],xy[6],xy[7],X3,Y3); double s2 = s - s1; if(s1 <= s2) { System.out.print(s1 + " "); System.out.println(s - s1); } else { System.out.print(s2 + " "); System.out.println(s - s2); } } } else if(d1 != 0&&d2 == 0&&d3 != 0&&d4 != 0) {//并且要与四边形有两个交点 System.out.println(sum); if(num34 == 1&&num12 == 0&& num23 ==0 &&num41 == 0) { double s1 = getArea(xy[2],xy[3],xy[4],xy[5],X3,Y3); double s2 = s - s1; if(s1 <= s2) { System.out.print(s1 + " "); System.out.println(s - s1); } else { System.out.print(s2 + " "); System.out.println(s - s2); } } if(num41 == 1&&num12 == 0&& num23 ==0 &&num34 == 0) { double s1 = getArea(xy[0],xy[1],xy[2],xy[3],X4,Y4); double s2 = s - s1; if(s1 <= s2) { System.out.print(s1 + " "); System.out.println(s - s1); } else { System.out.print(s2 + " "); System.out.println(s - s2); } } } else if(d1 != 0&&d2 != 0&&d3 == 0&&d4 != 0) {//并且要与四边形有两个交点 System.out.println(sum); if(num12 == 1&&num23 == 0&& num34 ==0 &&num41 == 0) { double s1 = getArea(xy[2],xy[3],xy[4],xy[5],X1,Y1); double s2 = s - s1; if(s1 <= s2) { System.out.print(s1 + " "); System.out.println(s - s1); } else { System.out.print(s2 + " "); System.out.println(s - s2); } } if(num41 == 1&&num12 == 0&& num23 ==0 &&num34 == 0) { double s1 = getArea(xy[4],xy[5],xy[6],xy[7],X4,Y4); double s2 = s - s1; if(s1 <= s2) { System.out.print(s1 + " "); System.out.println(s - s1); } else { System.out.print(s2 + " "); System.out.println(s - s2); } } } else if(d1 != 0&&d2 != 0&&d3 != 0&&d4 == 0) {//并且要与四边形有两个交点 System.out.println(sum); if(num12 == 1&&num23 == 0&& num34 ==0 &&num41 == 0) { double s1 = getArea(xy[6],xy[7],xy[0],xy[1],X1,Y1); double s2 = s - s1; if(s1 <= s2) { System.out.print(s1 + " "); System.out.println(s - s1); } else { System.out.print(s2 + " "); System.out.println(s - s2); } } if(num23 == 1&&num12 == 0&& num34 ==0 &&num41 == 0) { double s1 = getArea(xy[6],xy[7],xy[4],xy[5],X2,Y2); double s2 = s - s1; if(s1 <= s2) { System.out.print(s1 + " "); System.out.println(s - s1); } else { System.out.print(s2 + " "); System.out.println(s - s2); } } } } } }View Code
踩坑心得:刚开始的四边形的公式就用错了,并且还自己判断特别复杂,推荐不要自己判断,并且,一定要先设计好第四个点的思路,这个会很复杂,对于细节,一定要实现好,我就是第四个没有实现完全,推 荐大家多多去考虑。很多的公式要使用那种不需要考虑斜率的,这个是非常有必要的。
总结:在这段时间的学习中,更多的是需要改变C语言的写法,从C语言中走向面向对象设计,实现很多方法的使用,也多多使用继承和多态,这样可以实现代码的复用,能够大大减少代码的数量,同时也要改 变当初的写程序的方法,比如说以前都是直接拿起来写,我们需要,刚开始就设计好,可以大大减少时间,而不是盲目的去写,思路上也变清晰了在这里,我们学习了很多,比如说继承多态,向上转型, 向下转型,以及很多字符串的用法,还有正则表达式,这是一个比较好的方法,值得去推荐,相比于之前来说,现在对于类与类之间的设计,变得更加清晰明确,对于面向对象设计也越来越近,希望自己 能够以后更加努力加油,也希望大家能够一起加油!