dsa-competitive-programming/leetcode/lc1582/precompute1s.cpp

class Solution {
public:
    int numSpecial(vector<vector<int>>& mat) {
        int m = mat.size();
        int n = mat[0].size();
        vector<int> rowCount(m, 0);
        vector<int> colCount(n, 0);
        
        for (int row = 0; row < m; row++) {
            for (int col = 0; col < n; col++) {
                if (mat[row][col] == 1) {
                    rowCount[row]++;
                    colCount[col]++;
                }
            }
        }
        
        int ans = 0;
        for (int row = 0; row < m; row++) {
            for (int col = 0; col < n; col++) {
                if (mat[row][col] == 1) {
                    if (rowCount[row] == 1 && colCount[col] == 1) {
                        ans++;
                    }
                }
            }
        }
        
        return ans;
    }
};