判断矩阵是否是一个 X 矩阵【LC2319】

A square matrix is said to be an X-Matrix if both of the following conditions hold:

1.All the elements in the diagonals of the matrix are non-zero.

2.All other elements are 0.

Given a 2D integer array grid of size n x n representing a square matrix, return true if grid is an X-Matrix. Otherwise, return false.

感谢力扣 最近的都好简单 家里太忙了 没空学习了

• 思路：如果对角线的元素等于0或者其他元素不等于0，那么返回false

• 实现

class Solution {
    public boolean checkXMatrix(int[][] grid) {
        int n = grid.length;
        for (int i = 0; i < n; i++){
            for (int j = 0; j < n; j++){
                if (i == j || i + j == n - 1){
                    if (grid[i][j] == 0) return false;
                }else{
                    if (grid[i][j] != 0) return false;
                }
            }
        }
        return true;
    }
}

。复杂度

• 时间复杂度：O ( n ² ) ，n 为矩阵的长度
• 空间复杂度：O ( 1 )