LeetCode：2319. 判断矩阵是否是一个 X 矩阵

class Solution {
public:
    bool checkXMatrix(vector<vector<int>>& grid) {
        int n = grid.size();
        bool flag = true;
        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)
                    {
                        flag = false;
                        break;
                    }
                }
                else
                {
                    if(grid[i][j] != 0)
                    {
                        flag = false;
                        break;
                    }
                }
            }
        }
        return flag;
    }
};