Pat 1046 shortest distance (20 points) simulation

#include <iostream>
#include <vector>
using namespace std;
int main() {
       
    int n,m,sum=0,start,end;
    cin>>n;
    vector<int>a(n),dis(n+1);
    for(int i=1;i<n;i++){
    
        scanf("%d",&a[i]);
        dis[i+1]=dis[i]+a[i];    //dis[i] From the starting point to the i The distance between nodes 
        sum+=a[i];
    }
    scanf("%d",&a[0]);
    sum+=a[0];                   //sum Is the sum of the circular journey 
    cin>>m;
    for(int i=0;i<m;i++){
    
        cin>>start>>end;
        if(start>end) swap(start,end);
        int temp=dis[end]-dis[start];
        cout<<min(temp,sum-temp)<<endl;
    }
    return 0;
}