题解

上代码

#include<bits/stdc++.h>
using namespace std;
using ll=long long;
const ll N=1e5+10;
ll n,m,a[N],p[N];
int main(){
    cin>>n>>m;
    for(ll i=1;i<=n;i++){
        cin>>a[i];
        p[i]=p[i-1]+a[i];
    }
    while(m--){
        ll a,b;
        cin>>a>>b;
        cout<<p[b]-p[a-1]<<endl;
    }
    return 0;
}