写一个程序,在main方法里面定义一个数组,输出排序前的数组,将数组中的元素从小到大进行排序,输出排序后的数组。
package ZUOYE; import java.util.Scanner; public class A1 { public static void QuickSort(int num[],int n){ int i,j,temp; for(i = 0;i < n;i ++){ for(j = i + 1;j < n;j ++) if(num[i] > num[j]){ temp = num[i]; num[i] = num[j]; num[j] = temp; } } } public static void QuickSort(double num[],int n){ int i,j; double temp; for(i = 0;i < n;i ++){ for(j = i + 1;j < n;j ++) if(num[i] > num[j]){ temp = num[i]; num[i] = num[j]; num[j] = temp; } } } public static void main (String args[ ]) { int n,i,m; Scanner reader = new Scanner(System.in); System.out.println("要输入的元素数量为(数量少于10):"); n = reader.nextInt(); System.out.println("要输入的元素是否有小数(有则为1,无则为2):"); m = reader.nextInt(); if(m == 1){ double[] num; num = new double[10]; System.out.printf("请输入%d个元素:\n",n); for(i = 0;i < n; i ++) num[i] = reader.nextDouble(); System.out.println("排序前的元素数组为:"); for(i = 0;i < n; i ++) System.out.printf(num[i] + " "); QuickSort(num,n); System.out.println("\n排序后的元素数组为:"); for(i = 0;i < n;i ++) System.out.printf(num[i] + " "); } else if(m == 2){ int[] num; num = new int[10]; System.out.printf("请输入%d个元素:\n",n); for(i = 0;i < n; i ++) num[i] = reader.nextInt(); System.out.println("排序前的元素数组为:"); for(i = 0;i < n; i ++) System.out.printf(num[i] + " "); QuickSort(num,n); System.out.println("\n排序后的元素数组为:"); for(i = 0;i < n;i ++) System.out.printf(num[i] + " "); } } }
写一个方法,用来计算三角形的面积(参数为三个边长,实型,由键盘输入,面积计算用海伦公式:,p为三角形的半周长,使用方法Math.sqrt(),请查询JDK帮助文档,java.lang.Math类里面定义的方法),在main方法里面调用该方法,输出面积计算的结果。
package ZUOYE; import java.lang.Math; import java.util.Scanner; public class A1 { public static double Triang(double length,double width,double height){ double p = (length + width + height)/2; return Math.sqrt(p * (p - length) * (p - width) * (p - height)); } public static void main (String args[ ]) { Scanner reader = new Scanner(System.in); double length; double width; double height; System.out.println("请分别输入三角形的长,宽,高:"); length = reader.nextDouble(); width = reader.nextDouble(); height = reader.nextDouble(); System.out.println("三角形的面积为:" + Triang(length,width,height)); } }
使用一个二维数组存放如下图形的字符
*
package ZUOYE; import java.lang.Math; import java.util.Scanner; public class A1 { public static void main (String args[ ]) { int row = 0; int line = 0; int m = 0; char[][] s = {{'*'},{'*','*','*'},{'*','*','*','*','*'},{'*','*','*','*','#','*','*'}}; for(int i = 0;i < s.length;i ++) for(int j = 0;j < s[i].length;j ++) if(s[i][j] == '#'){ row = i; line = j; m = 1; } if(m == 1) System.out .println ("#的位置下标为" + "[" + row + "]" + "["+ line + "]" ); else System.out .println ("#不在该图形里!"); } }
* * *
* * * * *
* * * * # * *
找到字符#,并打印出它在二维数组中的下标。