1、猜数

import java.util.Scanner;
public class Main{
	public static void main(String[] args) {
		//Math.random()生成一个[0,1)的浮点数
		//Math.random()*100--->[0,100)
		//num--->[1,100]
		Scanner in = new Scanner(System.in);
		int num =(int)(Math.random()*100+1);
		int count = 0;
		int a;
		do
		{
			a = in.nextInt();
			count = count + 1;
			if(a>num)
			{
				System.out.println("偏大");
			}
			else if(a<num)
			{
				System.out.println("偏小");
			}
		}while(a != num);
		System.out.println("猜了"+count+"次");
	}
}

2、将整数逆序输出

import java.util.Scanner;
public class Main{
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		int num = in.nextInt();
		int result = 0;
		int digit;
		do
		{
			digit = num%10;
			num = num/10;
			result = result*10 + digit;
		}while(num>0);
		System.out.println(result);
	}
}

3、