第二周。

import java.util.Scanner;
public class Ex {
    public static void main(String[] args) {
        Scanner Lf=new Scanner(System.in);
        double x1,x2,y1,y2;
        System.out.println("请键入X1的值：");
        x1 = Double.valueOf(Lf.nextLine());
        System.out.println("请键入X2的值：");
        x2 = Double.valueOf(Lf.nextLine());
        System.out.println("请键入Y1的值：");
        y1 = Double.valueOf(Lf.nextLine());
        System.out.println("请键入Y2的值：");
        y2 = Double.valueOf(Lf.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));

    }
}