【模板】二维前缀和

#include<iostream>
#include<bits/stdc++.h>
using namespace std;
const int N= 1e3+3;
int n, m;
long long q,t,a[N][N];
int main(){
  cin>>n>>m>>q;
  for(int i= 1; i<= n; i++)
    for(int j= 1; j<= m; j++){
      cin>>t;
      a[i][j]= t+a[i][j-1]+a[i-1][j]-a[i-1][j-1];
    }
  while(q--){
        int x1,y1,x2,y2;
    cin>>x1>>y1>>x2>>y2;
     cout<<a[x2][y2]-a[x2][y1-1]-a[x1-1][y2]+a[x1-1][y1-1]<<endl;
    }
  return 0;
}