1.两点间距离 import java.util.Scanner; public class test {    public static void main(String[] args) {        Scanner Hy=new Scanner(System.in);        double x1,x2,y1,y2;        System.out.println("请键入X1的值：");        x1 = Double.valueOf(Hy.nextLine());        System.out.println("请键入X2的值：");        x2 = Double.valueOf(Hy.nextLine());        System.out.println("请键入Y1的值：");        y1 = Double.valueOf(Hy.nextLine());        System.out.println("请键入Y2的值：");        y2 = Double.valueOf(Hy.nextLine());        System.out.println("两个点之间的距离是："+ Math.pow((Math.pow((x2 - x1),2)+Math.pow((y2 - y1),2)),0.5));    }} 2.求一个整数个位数的和

import java.util.Scanner;public class test {    public static void main(String[] args) {        Scanner Hy=new Scanner(System.in);        String Hyper;        System.out.println("请输入一个0-1000的整数来求整数各位数的和");        Hyper = Hy.nextLine()        int test = Integer.valueOf(Hyper);        if(test > 0 && test <= 1000) {            int a = test % 2;            int b = test / 10;            int c = test / 100;            System.out.println("总和为：" + (a + b + c));        }        else {            System.out.println("完成！");        }