Question

I can not get this recursive binary search to wok for an edge case and it works but not for all, If you could look at it and try to find what is wrong to make this work for all edge cases.

//Write a function that will return true if an element k is found in an array of integers A and false otherwise. The input to your
//function is the array, its length 0 < n <= 10000, and the value of k. Assume that elements in the array are sorted in non-increasing
//order. Your algorithm must run in O(log n) time.

bool bin_search(const int *A, unsigned int n, int k){
if (n==0)
return false;
int mid = n/2;
if (A[mid] == k)
return true;
else if (k > A[mid])
return bin_search(A+mid-1, n-mid-1, k);
return bin_search(A, mid-1, k);
}

Answer 1

bool bin_search(const int *A, unsigned int n, int k){
    if (n==0)
        return false;
    int mid = n/2;
    if (A[mid] == k)
        return true;
    else if (k > A[mid])
        return bin_search(A+mid+1, n-mid-1, k);
    return bin_search(A, mid-1, k);
}