Search Tutorials

Loading...

Saturday, 20 April 2013

C code to implement Quick Sort

//C program to implement Quick Sort algorithm//

#include <stdio.h>
#include <stdlib.h>
#define MAXARRAY 10

void quicksort(int arr[], int low, int high);

int main(void)
{
int array[MAXARRAY] = {0};
int i = 0;
    clrscr();
    randomize();
 /* load some random values into the array */
for(i = 0; i < MAXARRAY; i++)
{
array[i] = rand() % 100; 
    }

 /* print the original array */
printf("Before quicksort: ");
for(i = 0; i < MAXARRAY; i++)
{
printf(" %d ", array[i]); 
}
printf("\n");

quicksort(array, 0, (MAXARRAY - 1));

 /* print the `quicksorted' array */
printf("After  quicksort: ");
for(i = 0; i < MAXARRAY; i++)
{
printf(" %d ", array[i]); 
}
printf("\n");
    getch();
return 0;
}

/* sort everything inbetween `low' <-> `high' */
void quicksort(int arr[], int low, int high)
{
int i = low;
int j = high;
int y = 0;
 /* compare value */
int z = arr[(low + high) / 2];

 /* partition */
do
{
  /* find member above ... */
while(arr[i] < z)
i++;

  /* find element below ... */
while(arr[j] > z)
j--;

if(i <= j)
{
   /* swap two elements */
y = arr[i];
arr[i] = arr[j]; 
arr[j] = y;
i++; 
j--;
}
}
while(i <= j);

 /* recurse */
if(low < j) 
quicksort(arr, low, j);

if(i < high) 
quicksort(arr, i, high); 
}

No comments:

Post a Comment

Back to Top