一维

#include<bits/stdc++.h>
using namespace std;

const int N = 1e5 + 10;
int n, m;
int a[N], p[N];


int main(){
    cin >> n >> m;
    for(int i = 1; i <= n; ++ i)
        cin >> a[i];

    for(int i = 1; i <= n; ++ i)
        p[i] = p[i - 1] + a[i];

    while(m --){
        int l, r;
        cin >> l >> r;
        cout << p[r] - p[l - 1] << endl;
    }


    return 0;
}

二维

#include<bits/stdc++.h>
using namespace std;

const int N = 1010;
int p[N][N];



int main(){
    int n, m, q;
    cin >> n >> m >> q;
    for(int i = 1; i <= n; ++ i)
        for(int j = 1; j <= m; ++ j)
            cin >> p[i][j];

    for(int i = 1; i <= n; ++ i)
        for(int j = 1; j <= m; ++ j)
            p[i][j] += p[i - 1][j] + p[i][j - 1] - p[i - 1][j - 1];

    while(q--){
        int x1, x2, y1, y2;
        cin >> x1 >> y1 >> x2 >> y2;
        cout << p[x2][y2] - p[x1 - 1][y2] - p[x2][y1 - 1] + p[x1 - 1][y1 - 1] << endl;
    }


    return 0;
}