1 def heap_sort(ary):
 2     n = len(ary)  # 8
 3     first = int(n / 2 - 1)  # 3
 4     for start in range(first, -1, -1):  # 3~0 revese
 5         max_heapify(ary, start, n - 1)  # from start
 6     for end in range(n - 1, 0, -1):
 7         ary[end], ary[0] = ary[0], ary[end]
 8         max_heapify(ary, 0, end - 1)
 9     return ary
10 
11 
12 def max_heapify(ary, start, end):
13     root = start
14     while True:
15         child = root * 2 + 1
16         if child > end:
17             break
18         if child + 1 <= end and ary[child] < ary[child + 1]:
19             child += 1
20         if ary[root] < ary[child]:
21             ary[root], ary[child] = ary[child], ary[root]
22             root = child
23         else:
24             break
25 
26 
27 def main():
28     ary = [6, 5, 3, 1, 8, 7, 2, 4]
29     heap_sort(ary)
30 
31     print(ary)
32 
33 main()

//Py自带的两种算法,一个sorted(ary)不影响本身结构,可ary.sort()就影响了

 

 1 def main():
 2     # ary = [6, 5, 3, 1, 8, 7, 2, 4]
 3     #heap_sort(ary)
 4 
 5     #print(ary)
 6 
 7     n = int(sys.stdin.readline())
 8     ary = [] # 申明一个数组
 9 
10     while n > 0:
11         ary.append(int(raw_input())) # 输入的排成数组
12         n -= 1
13 
14     ary.sort() #自带两种排序算法,.sort是真是变,sorter()是表面变
15     print '\n'.join(map(str, ary))  # map函数就是一个映射/转换,把list转换成string
16 
17 
18 main()

 

学习

  挑战了一把当年讳莫如深的堆排,现在理解其实不难,就是一个使用二叉来减少比较次数的快速排序

  各种py排序算法

    http://wuchong.me/blog/2014/02/09/algorithm-sort-summary/

  熟悉了通过查看文档来学习使用python的相关函数

  熟悉调用其自生的函数库

 

 posted on 2015-05-06 11:44  sangocare  阅读(189)  评论(0编辑  收藏  举报