Max sum in the configuration

//Given an array(0-based indexing), you have to find the max sum of i*A[i] where A[i] is the element at index i in the array. The only operation allowed is to rotate(clock-wise or counter clock-wise) the array any number of times.

//Input:
//N = 4
//A[] = {8,3,1,2}
//Output: 29
//Explanation: Above the configuration
//possible by rotating elements are
//3 1 2 8 here sum is 3*0+1*1+2*2+8*3 = 29
//1 2 8 3 here sum is 1*0+2*1+8*2+3*3 = 27
//2 8 3 1 here sum is 2*0+8*1+3*2+1*3 = 17
//8 3 1 2 here sum is 8*0+3*1+1*2+2*3 = 11
//Here the max sum is 29 


int max_sum(int A[],int N)
{
//Your code here
int sum =0;

int s[N];
s[0]=0;
for(int i=0;i<N;i++)
{ sum=sum+A[i];
 s[0]=A[i]*i+s[0];
}
int max=s[0];
for(int i=0;i<N-1;i++)
{s[i+1]=s[i]+sum-(N*A[N-1-i]);
 if(s[i+1]>max)
 max=s[i+1];
 s[i]=s[i+1];
}
return max;

}