1582. 二进制矩阵中的特殊位置

approach 1

class Solution {
    public int numSpecial(int[][] mat) {
        int r = mat.length, c = mat[0].length;
        int[] row = new int[r];
        int[] col = new int[c];
        for (int i = 0; i < r; i++) {
            for (int j = 0; j < c; j++) {
                if (mat[i][j] == 1) {
                    row[i]++;
                    col[j]++;
                }
            }
        }
        
        int cnt = 0;
        for (int i = 0; i < r; i++) {
            for (int j = 0; j < c; j++) {
                if (mat[i][j] == 1 && row[i] == 1 && col[j] == 1) {
                    cnt++;
                }
            }
        }
        
        return cnt;
    }
}