Cuboid Sum Query

看时间限制发现用不上三维前缀和，就做个二维前缀和就行了，余下的一维暴力求和就行。

很典。

#include <bits/stdc++.h>

using i64 = long long;

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    int N;
    std::cin >> N;
    std::vector<std::vector<std::vector<i64>>> a(
        N + 1,
        std::vector<std::vector<i64>>(N + 1, std::vector<i64>(N + 1, 0)));

    for (int i = 1; i <= N; i++) {
        for (int j = 1; j <= N; j++) {
            for (int k = 1; k <= N; k++) {
                std::cin >> a[i][j][k];
            }
        }
    }

    for (int i = 1; i <= N; i++) {
        for (int j = 1; j <= N; j++) {
            for (int k = 1; k <= N; k++) {
                a[i][j][k] = a[i][j - 1][k] + a[i][j][k - 1] -
                            a[i][j - 1][k - 1] + a[i][j][k];
            }
        }
    }

    int q;
    std::cin >> q;

    while (q--) {
        int l[4], r[4];
        std::cin >> l[1] >> r[1] >> l[2] >> r[2] >> l[3] >> r[3];

        i64 sum = 0;
        for (int i = l[1]; i <= r[1]; i++) {
            sum += a[i][r[2]][r[3]] + a[i][l[2] - 1][l[3] - 1] -
                a[i][l[2] - 1][r[3]] - a[i][r[2]][l[3] - 1];
        }

        std::cout << sum << '\n';
    }

    return 0;
}