正方形

Problem Description
给出四个点，判断这四个点能否构成一个正方形。
Input
输入的第一行包含一个整数T（T≤30）表示数据组数，每组数据只有一行，包括8个整数x1, y1, x2, y2，x3，y3，x4，y4（数据均在-1000,1000 之间）以逆时针顺序给出四个点的坐标。

Output
每组数据输出一行，如果是正方形，则输出： YES， 否则，输出：NO。

Sample Input
2
0 0 1 0 1 1 0 1
-1 0 0 -2 1 0 2 0
Sample Output
YES
NO

import java.util.*;
import java.text.*;
class Square{
    int x;
    int y;
    public Square(int x, int y) {
        super();
        this.x = x;
        this.y = y;
    }
    public double distance(Square s) {
        return Math.pow((x-s.x), 2) + Math.pow((y-s.y), 2);
    }

}
public class Main {

    public static void main(String[] args) throws ParseException {
        Scanner sc = new Scanner(System.in);
        int T = sc.nextInt();
        while(T-- != 0) {
            Square s1 = new Square(sc.nextInt(), sc.nextInt());
            Square s2 = new Square(sc.nextInt(), sc.nextInt());
            Square s3 = new Square(sc.nextInt(), sc.nextInt());
            Square s4 = new Square(sc.nextInt(), sc.nextInt());
            if(s1.distance(s2) == s1.distance(s4) && s1.distance(s3) == s2.distance(s4) && s3.distance(s2) == s3.distance(s4) 
                    && s4.distance(s1) == s4.distance(s3))//逆时针,对角线相等
            {
                System.out.println("YES");
            }
            else {
                System.out.println("NO");
            }
        }
        sc.close();
    }
}

来源：CSDN

作者：sugargx

链接：https://blog.csdn.net/gx17864373822/article/details/79872983