Given an array of integers. Find the sum of all intergers using Recursion.

#include <iostream>
#include <cstdio>
using namespace std;
#define siz 1000005
int a[siz];

int list_sum(int a[], int n, int i){
    if(i == n) return 0;
    return a[i] + list_sum(a, n, i+1);
}

int main()
{
    int n;
    //freopen("input.txt","r",stdin);
    while(scanf("%d",&n)==1){
        for(int i=0; i<n; i++){
            scanf("%d",&a[i]);
        }
        cout<<list_sum(a, n, 0)<<endl;
    }
    return 0;
}