题解 | 【模板】二维前缀和

#include <iostream>
using namespace std;
const int maxn = 1005;
typedef long long LL;
LL sum[maxn][maxn];
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n, m, q;
    cin >> n >> m >> q;
    int x;
    LL cur = 0;
    for(int i=1; i<=n; i++){
        for(int j=1; j<=m; j++){
            cin >>x;
            cur += x;
            sum[i][j] = cur - (sum[i-1][m] - sum[i-1][j]);
        }
    }
    int x1,x2,y1,y2;
    for(int i=0; i<q; i++){
        cin >> x1 >> y1 >> x2 >> y2;
        LL tmp1 = sum[x1-1][y2];
        LL tmp2 = sum[x2][y1-1];
        cout << sum[x2][y2] - tmp1 -tmp2 + sum[x1-1][y1-1] << endl;
    }
}
// 64 位输出请用 printf("%lld")