归并排序最令人兴奋的特点是:不论输入是什么样的,它对N个元素的序列排序所用时间与NlogN成正比。代码如下:
def mergesort(seq):
if len(seq)<=1:
return seq
mid=int(len(seq)/2)
left=mergesort(seq[:mid])
right=mergesort(seq[mid:])
return merge(left,right)
def merge(left,right):
result=[]
i,j=0,0
while i<len(left) and j<len(right):
if left[i]<=right[j]:
result.append(left[i])
i+=1
else:
result.append(right[j])
j+=1
result+=left[i:]
result+=right[j:]
return result
if __name__=='__main__':
seq=[4,5,7,9,7,5,1,0,7,-2,3,-99,6]
print(mergesort(seq))
转载请注明: 转自
http://blog.csdn.net/littlethunder/article/details/9472301