Implementation of quick sort to sort an two dimensional array. Usage example included.

twoDimQS.c

#include <stdio.h>
#include <stdlib.h>
#define N 4

void swap(int *a, int *b) {
    int temp;
    temp = *a;
    *a = *b;
    *b = temp;
}

void quickSort(int arr[], int lowPos, int highPos) {
    int low_Pos = lowPos; // Local Variable - Limit of low position
    int high_Pos = highPos; // Limit of high position
    int * arr_ptr = (int*) arr;
    int pivot = *(arr_ptr + ((low_Pos + high_Pos) / 2));
    do {
        while (*(arr_ptr + low_Pos) < pivot) low_Pos++; /*find item above pivot*/
        while (*(arr_ptr + high_Pos) > pivot) high_Pos--; /* find item below pivot */

        if (low_Pos <= high_Pos) {
            swap((arr_ptr + low_Pos), (arr_ptr + high_Pos));
            low_Pos++;
            high_Pos--;
        }
    } while (low_Pos <= high_Pos);

    //quick sort' the partitions recursively
    if (lowPos < high_Pos)
        quickSort(arr, lowPos, high_Pos);

    if (low_Pos < highPos)
        quickSort(arr, low_Pos, highPos);
}

int main() {
    int arr[N][N];
    int *arr_ptr = arr;
    int row, column;

    for (row = 0; row < N; row++) {
        for (column = 0; column < N; column++) {
            arr[row][column] = 1 + rand() % 10;
        }
    }

    printf("The array before sorting :\n");
    for (row = 0; row < N; row++) {
        for (column = 0; column < N; column++) {
            printf("%3d", arr[row][column]);
        }
        printf("\n");
    }

    quickSort(arr_ptr, 0, (N * N) - 1);

    printf("\nThe array after sorting :\n");
    for (row = 0; row < N; row++) {
        for (column = 0; column < N; column++) {
            printf("%3d", arr[row][column]);
        }
        printf("\n");
    }
    exit(EXIT_SUCCESS);
}