题解 | 【模板】二维前缀和

#include <iostream>
using namespace std;
#define int long long
const int N=1e3+10;
int a[N][N];
int s[N][N];
int n,m,q;

signed main()
{
    cin>>n>>m>>q;
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=m;j++)
        {
            cin>>a[i][j];
        }
    }
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=m;j++)
        {
            s[i][j]=s[i-1][j]+s[i][j-1]-s[i-1][j-1]+a[i][j];
        }
    }
    int x1,y1,x2,y2;
    while(q--)
    {
        cin>>x1>>y1>>x2>>y2;
       // cout<<s[x2][y2]<<' '<<s[x1][y2]<<' '<<s[x2][y1]<<' '<<s[x1-1][y1-1]<<endl;
        cout<<s[x2][y2]-s[x1-1][y2]-s[x2][y1-1]+s[x1-1][y1-1]<<endl;
    }
}