build a prefix array cpp

1void fillPrefixSum(int arr[], int n, int prefixSum[]) 
2{ 
3    prefixSum[0] = arr[0]; 
4  
5    // Adding present element 
6    // with previous element 
7    for (int i = 1; i < n; i++) 
8        prefixSum[i] = prefixSum[i - 1] + arr[i]; 
9}