题解 | #【模板】二维前缀和#

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

int main() {
    //1.读入数据
    int n = 0,m = 0,q = 0;
    cin>>n>>m>>q;
    vector<vector<int>> arr(n+1,vector<int>(m+1));
    for(int i = 1;i<=n;i++)
        for(int j = 1;j<=m;j++)
            cin>>arr[i][j];
    //2.预处理前缀和矩阵
    vector<vector<long long>> dp(n+1,vector<long long>(m+1));
    for(int i = 1;i<=n;i++)
        for(int j = 1;j<=m;j++)
            dp[i][j] =dp[i-1][j]+dp[i][j-1]+arr[i][j]-dp[i-1][j-1];
    //3.使用前缀和矩阵
    int x1 = 0,x2 = 0,y1 = 0,y2 = 0;
    while(q--)
    {
        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")