python实现的堆排序算法代码，python堆排序算法,python实现的堆排序

python实现的堆排序算法代码，python堆排序算法,python实现的堆排序

python实现的堆排序算法代码

def heapSort(a):     def sift(start, count):         root = start         while root * 2 + 1 < count:             child = root * 2 + 1             if child < count - 1 and a[child] < a[child + 1]:                 child += 1             if a[root] < a[child]:                 a[root], a[child] = a[child], a[root]                 root = child             else:                 return     count = len(a)     start = count / 2 - 1     end = count - 1     while start >= 0:         sift(start, count)         start -= 1     while end > 0:         a[end], a[0] = a[0], a[end]         sift(0, end)         end -= 1 a = [-8,0,1,3,11,35,68] heapSort(a) print a # [-8, 0, 1, 3, 11, 35, 68]

Recursive sift(and more readable IMHO) Version:```pythondef heapsort(a):

def swap(a,i,j):     tmp = a[i]     a[i] = a[j]     a[j] = tmpdef siftdown(a, i, size):     l = 2*i+1     r = 2*i+2     largest = i     if l <= size-1 and a[l] > a[i]:         largest = l     if r <= size-1 and a[r] > a[largest]:         largest = r     if largest != i:         swap(a, i, largest)         siftdown(a, largest, size)def heapify(a, size):     p = (size/2)-1     while p>=0:         siftdown(a, p, size)         p -= 1size = len(a)         heapify(a, size) end = size-1 while(end > 0):     swap(a, 0, end)     siftdown(a, 0, end)     end -= 1

```