Forest density

#include <iostream>
#include <vector>
using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, q;
    cin >> n >> q;
    vector<vector<int>> p(n + 1, vector<int>(n + 1, 0));
    for (int y = 1; y <= n; y++) {
        string row;
        cin >> row;
        for (int x = 1; x <= n; x++) {
            p[y][x] = (row[x - 1] == '*') + p[y - 1][x] + p[y][x - 1] - p[y - 1][x - 1];
        }
    }
    while (q--) {
        int y1, x1, y2, x2;
        cin >> y1 >> x1 >> y2 >> x2;
        cout << p[y2][x2] - p[y1 - 1][x2] - p[y2][x1 - 1] + p[y1 - 1][x1 - 1] << "\n";
    }
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED