力扣：1582. 二进制矩阵中的特殊位置

class Solution {
    public int numSpecial(int[][] mat) {
         int n = mat.length, m = mat[0].length;
        int[] row = new int[n];
        int[] col = new int[m];
        // 计算出行和列出现1的个数
        for (int i = 0; i < n; i++){
            for (int j = 0; j < m; j++){
                row[i] += mat[i][j];
                col[j] += mat[i][j];
            }
        }
        int res = 0;
        for (int i = 0; i < n; i++){
            for (int j = 0; j < m; j++){
                if (mat[i][j] == 1 && row[i] == 1 && col[j] == 1){
                    res++;
                }
            }
        }
        return res;
    }
}