Question

I’m trying to get quicksort working to sort an array of 7000 strings into alphabetical order, but all i’m getting is a blank output file. It works fine with my bubblesort method, but not with this. I’m sure it’s an obvious mistake, but i can’t pin-point it.

void ArrayStorage::quicksort(int first, int last, string list[])
{
        int middle, p, index;
    string temp, partition;
    if (first < last)
    {  
            middle = int(first + last)/2;
            temp = list[middle];
            list[middle] = list[first];
            list[first] = temp;
            partition = list[first];
            p = first;
            for (index = first + 1; index <= last; index++)
            {
                    if(list[index] < partition)
                    {
                            p = p + 1;
                            temp = list[index];
                            list[index] = list[p];
                            list[p] = temp;
                    }  
            }  
            temp = list[first];
            list[first] = list[p];
            list[p] = temp;
            quicksort(first, p - 1, list);
            quicksort(p + 1, last, list);
    }
}

I call the method like this:

  quicksort(0,GetSize() -1,namesArray);

Answer 1

How about using the built in quicksort?:

std::sort(&namesArray[0], &namesArray[GetSize()]);