题解 | 【模板】二维前缀和

#include <iostream>
#include <vector>
using namespace std;
using ll=long long;

int main()
{
    int n,m,q;cin>>n>>m>>q;

    vector<vector<ll>> arr(n+10,vector<ll>(m+10,0));
    vector<vector<ll>> dp(n+10,vector<ll>(m+10,0));

    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=m;j++)
        {
            cin>>arr[i][j];
            dp[i][j]=dp[i-1][j]+dp[i][j-1]+arr[i][j]-dp[i-1][j-1];
        }
    }

    for(int cnt=0;cnt<q;cnt++)
    {
        int x1,y1,x2,y2;
        cin>>x1>>y1>>x2>>y2;
        ll result=dp[x2][y2]-dp[x1-1][y2]-dp[x2][y1-1]+dp[x1-1][y1-1];
        cout<<result<<endl;
    }
    return 0;
}