Created
August 24, 2012 10:30
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Python quicksort comparision
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from random import randint | |
import timeit | |
import sys | |
def qsort2(list): | |
if list == []: | |
return [] | |
else: | |
pivot = list[0] | |
lesser, equal, greater = partition(list[1:], [], [pivot], []) | |
return qsort2(lesser) + equal + qsort2(greater) | |
def partition(list, l, e, g): | |
if list == []: | |
return (l, e, g) | |
else: | |
head = list[0] | |
if head < e[0]: | |
return partition(list[1:], l + [head], e, g) | |
elif head > e[0]: | |
return partition(list[1:], l, e, g + [head]) | |
else: | |
return partition(list[1:], l, e + [head], g) | |
def qsort(list): | |
if list == []: | |
return [] | |
pivot = list[0] | |
l = qsort([x for x in list[1:] if x < pivot]) | |
u = qsort([x for x in list[1:] if x >= pivot]) | |
return l + [pivot] + u | |
def get_array(n): | |
l = [] | |
for i in range(n): | |
l.append(randint(0,n)) | |
return l | |
def test(n,i): | |
x=get_array(n) | |
if i is 1: | |
qsort(x) | |
else: | |
qsort2(x) | |
if __name__=="__main__": | |
sys.setrecursionlimit(10000) | |
print "list-compr 1000 elems",timeit.Timer("test(1000,1)",setup="""from __main__ import test""").timeit(100) | |
print "recursion 1000 elems",timeit.Timer("test(1000,2)",setup="""from __main__ import test""").timeit(100) | |
print "list-compr 2000 elems",timeit.Timer("test(2000,1)",setup="""from __main__ import test""").timeit(100) | |
print "recursion 2000 elems",timeit.Timer("test(2000,2)",setup="""from __main__ import test""").timeit(100) | |
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