Function kepps after return ( Recursion C)

Question

This is my code:

int Binary (int* arr, unsigned int size, int num)
{

    if (0 == size)
    {
        return -1;
    }
    if (1 == size)
    {
        if (arr[0] == num)
        {
            return 0;
        }    
        return -1;
    }

    size/= 2;
    if (num == arr[size])
    {
        return size;
    }
    else
    {
        if (num < arr[size])
        {
            Binary (arr, size, num);
        }
        else
        {
            Binary (&arr[size+1], size, num);
        }
    }

    return -1;
}

It doesn't work. When I debug it (trying to search a number that appears in an array), I see that it goes into the line of 'return size', which it should do (side question- is there a way to put line numbers in the code..) but then it keeps going to the last line and returns -1. How come I have a return and it doesn't go out of the function? I first tried not to put any return in the end because I am not supposed to reach to the end, but the compiler says "control reaches end of non-void function" so I added the last return, but obviously it is not the right thing to do..

Thanks

Answer 1

You should return the results of the recursive call

int Binary (int* arr, unsigned int size, int num)
{

    if (0 == size)
    {
        return -1;
    }
    if (1 == size)
    {
        if (arr[0] == num)
        {
            return 0;
        }    
        return -1;
    }

    size/= 2;
    if (num == arr[size])
    {
        return size;
    }
    else
    {
        if (num < arr[size])
        {
            return Binary (arr, size, num); // Added return
        }
        else
        {
            return Binary (&arr[size+1], size, num); // Added return
        }
    }
}