C Program to Perform Quick Sort on a set of Entries from a File using Recursion
Posted by Superadmin on December 09 2015 04:55:50

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The following C program, using recursion, performs quick sort. A quick sort is a sorting algorithm with complexity of O(nlogn). It is used for sorting numbers, structure, files.

Here is the source code of the C program to display a linked list in reverse. The C program is successfully compiled and run on a Linux system. The program output is also shown below.

/*
* C Program to Perform Quick Sort on a set of Entries from a File
* using Recursion
*/
#include <stdio.h>

void quicksort (int [], int, int);

int main()
{
int list[50];
int size, i;

printf("Enter the number of elements: ");
scanf("%d", &size);
printf("Enter the elements to be sorted:\n");
for (i = 0; i < size; i++)
{
scanf("%d", &list[i]);
}
quicksort(list, 0, size - 1);
printf("After applying quick sort\n");
for (i = 0; i < size; i++)
{
printf("%d ", list[i]);
}
printf("\n");

return 0;
}
void quicksort(int list[], int low, int high)
{
int pivot, i, j, temp;
if (low < high)
{
pivot = low;
i = low;
j = high;
while (i < j)
{
while (list[i] <= list[pivot] && i <= high)
{
i++;
}
while (list[j] > list[pivot] && j >= low)
{
j--;
}
if (i < j)
{
temp = list[i];
list[i] = list[j];
list[j] = temp;
}
}
temp = list[j];
list[j] = list[pivot];
list[pivot] = temp;
quicksort(list, low, j - 1);
quicksort(list, j + 1, high);
}
}

$ cc pgm29.c
$ a.out
Enter the number of elements: 6
Enter the elements to be sorted:
67
45
24
98
12
38
After applying quick sort
12 24 38 45 67 98