Queen Attack

• Time : $O(nm)$
• Space : $O(n + m)$

vector<vector<int>> Solution::queenAttack(vector<string> &A) {
    int n = A.size(), m = A[0].length();
    vector<int> r1(n), c1(m);
    unordered_map<int, int> dig1, adig1;
    vector<int> r2(n), c2(m);
    unordered_map<int, int> dig2, adig2;
    auto add = [&](int i, int j, int v) {
        r1[i] += v;
        c1[j] += v;
        dig1[i - j] += v;
        adig1[i + j] += v;
    };
    auto add2 = [&](int i, int j, int v) {
        r2[i] += v;
        c2[j] += v;
        dig2[i - j] += v;
        adig2[i + j] += v;
    };
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            if(A[i][j] == '0') continue;
            add(i,j,1);
        }
    }
    vector<vector<int>> res(n,vector<int>(m));
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            if(A[i][j] == '1') add(i,j,-1);
            res[i][j] = (r1[i] > 0) + (r2[i] > 0) + (c1[j] > 0) + (c2[j] > 0) + (dig1[i-j] > 0) + (dig2[i-j] > 0) + (adig1[i + j] > 0) + (adig2[i + j] > 0);
            if(A[i][j] == '1') add2(i,j,1);
        }
    }
    return res;
}