Quicksort algorithm crashing & debugging help

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C

algorithm

debugging

Dear all,

I'm stuck on code below and can't seem to figure out why it keeps crashing. It's supposed to be a simple quicksort algorithm in C but it's giving me a segmentation fault and crashing after I enter the input. I debugged it with Dev C++ and it shows that it's crashing in the recursive calls of quicksort. Can anyone point out where?

Also, for a program like this, can anyone point out a debugger or technique that will help me fix this myself? I have other such programs that I will need to test / practice and I don't want to keep having to post like this. Thanks all in advance.

/* includes and macros */
// required for input / output with minGW GCC
#include <stdio.h>
#define printf __mingw_printf

// required for the random integer generator functions
#include <stdlib.h>
#include <time.h>


/* global declarations */
static unsigned short n;

/* function prototypes */
void swapSort(int *, int *);
void quickSortMid(int [], unsigned short, unsigned short);


int main()
{
    /* variable array declaration */
    printf("How many integers do you want sorted by Quick Sort? ");
    scanf("%hu", &n);
    int arrayInput[n];

    /* for rand() */
    srand(time(NULL));

    /* array input */
    printf("\n");
    for(register unsigned short i = 0; i <= n-1; i++)
        arrayInput[i] = rand();

    /* sort using the Quick Sort Medium algorithm */
    quickSortMid(arrayInput, 0, n-1);

    /* print the sorted array */
    printf("\n");
    for(register unsigned short i = 0; i <= n-1; i++)
        printf("[%d] ", arrayInput[i]);
    printf("\n");

    return 0;
}


/* function definitions */
void swapSort(int *a, int *b)
{
    int temp = *a;
    *a = *b;
    *b = temp;
}


void quickSortMid(int intArray[], unsigned short low, unsigned short high)
{
    unsigned short e = high / 2, hole = e, ul = high;
    int temp = intArray[e];
    while(low < high)
    {
        if(hole >= e)
        {
            if(intArray[low] > temp)
            {
                swapSort(&intArray[low], &intArray[hole]);
                hole = low;
            }
            else low++;
        }
        else
        {
            if(intArray[high] < temp)
            {
                swapSort(&intArray[high], &intArray[hole]);
                hole = high;
            }
            else high--;
        }
    }
    intArray[hole] = temp;

    // recursive calls of Quick Sort to completely sort the array
    if(e >= 2 && (ul-e) >= 2)
    {
        quickSortMid(intArray, 0, e-1);
        quickSortMid(intArray, e+1, ul);
    }
}

What I have tried:

I have tried debugging with Dev C++ and have narrowed the problem to the recursive calls of the function but can't seem to figure out what's wrong with the logic.

Downloaded many different debuggers and read much on debugging but nothing that will help me learn properly how to debug my own programs. If this were a simple logic problem, then I could use printf to see where the sorting was wrong and why but the program is crashing.