题解 | 绕距

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);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int x1 = in.nextInt();
            int y1 = in.nextInt();
            int x2 = in.nextInt();
            int y2 = in.nextInt();

            int e=(x1-x2)*(x1-x2)+(y1-y2)*(y1-y2);

            double de =Math.sqrt(e);
            int dm=Math.abs(x1-x2)+Math.abs(y1-y2);

            double dert =Math.abs(dm-de);
            System.out.println(dert);
        }
    }
}