题解 | #对称矩阵#

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 n = in.nextInt();
            int [][]a = new int[n][n];
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < n; j++) {
                    a[i][j] = in.nextInt();
                }
            }
            boolean flag = true;
            for (int i = 0; i < n; i++) {
                for (int j = i + 1; j < n; j++) {
                    if (a[i][j] != a[j][i])
                        flag = false;
                }
            }
            if (flag == false)
                System.out.println("No!");
            else
                System.out.println("Yes!");
            // int b = in.nextInt();
            // System.out.println();
        }
    }
}