标准题解

#include<bits/stdc++.h>
using namespace std;
int n,m;
int a[100005],QZH[100005];
int main(){
	cin>>n>>m;
	for(int i = 0;i < n;i++){
		cin>>a[i];
		QZH[i + 1] = QZH[i] + a[i];
	}
	for(int i = 1;i <= m;i++){
		int l,r;
		cin>>l>>r;
		cout<<QZH[r] - QZH[l - 1]<<endl;
	}
	return 0;
}