题解 | #【模板】二维前缀和#

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

int main()
{
    int n = 0, m = 0, q = 0;
    cin >> n >> m >> q;
    vector<vector<long long>> nums(n+1, vector<long long>(m+1));
    for (int i = 1; i < n + 1; ++i)
    {
        for (int j = 1; j < m + 1; ++j)
        {
            cin >> nums[i][j];
        }
    }
    // 创建前缀和矩阵
    vector<vector<long long>> dp(n + 1, vector<long long>(m + 1));
    for (int i = 1; i < n + 1; ++i)
    {
        for (int j = 1; j < m + 1; ++j)
        {
            dp[i][j] = dp[i - 1][j] + dp[i][j - 1] + nums[i][j] - dp[i - 1][j - 1];
        }
    }
    // 使用前缀和矩阵
    while (q--)
    {
        int x1 = 0, y1 = 0, x2 = 0, y2 = 0;
        cin >> x1 >> y1 >> x2 >> y2;
        cout << (dp[x2][y2] - dp[x1-1][y2] - dp[x2][y1-1] + dp[x1 - 1][y1 - 1]) << endl;
    }
    return 0;
}
// 64 位输出请用 printf("%lld")