题解

#include<iostream>
#include<vector>
using namespace std;
int main(){
    int n,m; scanf("%d%d",&n,&m);
    vector<int> nu;
    for(int i=0; i<n; i++){int tmp; scanf("%d",&tmp); nu.push_back(tmp);}
    while(m--){
        int a,b,ans=0; scanf("%d%d",&a,&b);
        for(int i=a-1; i<b; i++){ans+=nu[i];}
        printf("%d\n",ans);
    }
    return 0;
}