C :

int a[20];
int main() 
{
	int n,i;
	scanf("%d",&n);
	for(i = 0; i < n; i++) 
	{
		scanf("%d",&a[i]);
	}
	int max= 0;         //最大值
	int maxIndex = 0;  //起始位置下标
	for(i = 0; i < n; i++) 
	{
		int num = a[i] + a[ (i + 1) % n  ]  + a[  (i + 2) % n  ] + a[  (i + 3) % n  ];
		if(num > max) 
		{
			max = num;
			maxIndex = i;
		}
	}
	printf("%d %d",max,maxIndex+1);
}

C++ :

#include <bits/stdc++.h>
using namespace std;
int main()
{
    int a[150],n,zf,s,max,p;
    bool f;
    cin>>n;
    for (int i=0;i<n;i++)
    {
        cin>>a[i];
        
    }
    max=a[0]+a[(0+1)%n]+a[(0+2)%n]+a[(0+3)%n];
    p=0;
    for (int i=0;i<n;i++)
    {
    	s=a[i]+a[(i+1)%n]+a[(i+2)%n]+a[(i+3)%n];
    	if (s>max) 
		{
			max=s;
			p=i;
		}
    	
	}
	cout<<max<<endl<<p+1<<endl;
    return 0;
}
 

Python :

n = int(input())
li = list(map(int,input().split()))
li.append(li[0]) 
li.append(li[1])
li.append(li[2])
m = 0
s = 0
for i in range (0,n):
    r = li[i] + li[i + 1] + li[i + 2] + li[i + 3]
    if r > m:
        m = r
        s = i 
print(m)
print(s+1)