题解

#include<bits/stdc++.h>
using namespace std;
int n[114514],s[114514];
int main(){
	int a,b;
	cin>>a>>b;
	for(int i=1;i<=a;i++){
		cin>>n[i];
        s[i]+=s[i-1]+n[i];
	}
	int x,y;
	for(int i=1;i<=b;i++){
		cin>>x>>y;
		cout<<s[y]-s[x-1]<<endl;
	}
}