QuickSort python example.

quicksort.py

import random

def sort(a,low,high):
	if low>=high:
		return
	i = low
	j = high
	mid_value = a[i]

	while(True):
		while (a[i]>=mid_value):
			i+=1
			if i==high:
				break

		while (a[j]<=mid_value):
			j-=1
			if j==low:
				break
		if (i>=j):
			break
		a[i],a[j] = a[j],a[i]

	a[low],a[j] = a[j],a[low]
	sort(a,low,j-1)
	sort(a,j+1,high)

def main(a):
	random.shuffle(a)
	sort(a,0,len(a)-1)

if __name__ == "__main__":
	a = []
	for i in range(1000):
		a.append(random.randint(-1000,1000))

	main(a)
	print a