python 实现归并排序算法

#!/usr/bin/python
import sys

def merge(array,q,p,r):
left_array = array[q:p+1]
right_array = array[p+1:r+1]

left_array_num = len(left_array)
right_array_num = len(right_array)

i,j,k= [0,q]
while i < left_array_num and j < right_array_num:
if (left_array[i] < right_array[j]):
array[k] = left_array[i]
i+=1
else:
array[k] = right_array[j]
j+=1
k+=1

while i < left_array_num:
array[k] = left_array[i];
k+=1
i+=1

while j < right_array_num:
array[k] = right_array[j]
k+=1
j+=1

def merge_sort(array,r):
if q < r:
p = (q + r) / 2
merge_sort(array,p)
merge_sort(array,p + 1,r)
merge(array,r)

if __name__ == "__main__":
array = [2,45,5,7,34,456,345,89,8,1,341,4,98,67]
merge_sort(array,len(array) - 1)

for a in array:
sys.stdout.write("%d " % a)