Quick-sort Source-Code

November 27th, 2007

Filed under: Algorithms — Unggul_USA @ 2:20 pm — View blog reactions

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#define NUM_ITEMS 51
void quickSort(int numbers[], int array_size);
void q_sort(int numbers[], int left, int right);
int numbers[NUM_ITEMS];
int counter;
// timestart, timestop;
int main()
{
int i; //seed random number generator
srand(getpid()); //fill array with random integers
//printf(time());
for (i = 0; i < NUM_ITEMS; i++)
numbers[i] = rand();
quickSort(numbers, NUM_ITEMS); //perform quick sort on array
counter=0;
quickSort(numbers, NUM_ITEMS); //perform quick sort on array
for (i = 0; i < NUM_ITEMS; i++)
printf(”%i\n”, numbers[i]);
//timestop = time();
printf(”Done with sort.\n”);
printf(”%i %i\n”, i,counter);
//printf(”%u %u\n”, timestart,timestop);
}
void quickSort(int numbers[], int array_size)
{
q_sort(numbers, 0, array_size - 1);
}
void q_sort(int numbers[], int left, int right)
{
int pivot, l_hold, r_hold;
l_hold = left;
r_hold = right;
pivot = numbers[left];
while (left < right)
{
while ((numbers[right] >= pivot) && (left < right))
right–;
if (left != right)
{
numbers[left] = numbers[right];
left++;
}
counter++;
while ((numbers[left] <= pivot) && (left < right))
left++;
if (left != right)
{
numbers[right] = numbers[left];
right–;
}
counter++;
}
numbers[left] = pivot;
pivot = left;
left = l_hold;
right = r_hold;
if (left < pivot)
q_sort(numbers, left, pivot-1);
if (right > pivot)
q_sort(numbers, pivot+1, right);
}