题解 | #牛牛的线段#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
       int x1 = in.nextInt();
       int y1 = in.nextInt();
       int x2 = in.nextInt();
       int y2 = in.nextInt();

       double m = Math.pow((x1-x2),2)+Math.pow((y1-y2),2);

       System.out.printf("%d",(int)m);
    }
}