DOANLT C++

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

int n,m,x,y;
long long s;
int a[1000009], f[1000009];

void doc ()
{
    //scanf("%d", &n);
    cin>>n;
    for (int i=1;i<=n;i++) 
        //scanf("%d", &a[i]);
        cin>>a[i];
    
}

void tinh_f()
{
    f[0]=0;
    for (int i=1;i<=n;i++) f[i] = f[i-1] + a[i];
}

void xuly()
{
    //scanf("%d", &m);
    cin>>n;
    for (int i=1;i<=m;i++)
    {
        //scanf("%d %d", &x, &y);
        cin>>x>>y;
        s = f[y] - f[x-1];
        //printf("%lld\n", s);
        cout<<s<<endl;
    }
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);

    freopen("DOANLT.inp", "r", stdin);
    freopen("DOANLT.out", "w", stdout);
    doc();
    tinh_f();
    xuly();
}