堆排序的原理這裏就不說了,數據結構裏好好查一查吧。
大致原理就是通過不斷地構建大根堆(小根堆),交換根節點和尾節點的值,再重複地調整堆來完成排序。
代碼如下:
import random
def MAX_Heapify(heap,HeapSize,root):#在堆中做結構調整使得父節點的值大於子節點
left = 2*root + 1
right = left + 1
larger = root
if left < HeapSize and heap[larger] < heap[left]:
larger = left
if right < HeapSize and heap[larger] < heap[right]:
larger = right
if larger != root:#如果做了堆調整則larger的值等於左節點或者右節點的,這個時候做對調值操作
heap[larger],heap[root] = heap[root],heap[larger]
MAX_Heapify(heap, HeapSize, larger)
def Build_MAX_Heap(heap):#構造一個堆,將堆中所有數據重新排序
HeapSize = len(heap)#將堆的長度當獨拿出來方便
for i in range((HeapSize -2)//2,-1,-1):#從後往前出數
MAX_Heapify(heap,HeapSize,i)
def HeapSort(heap):#將根節點取出與最後一位做對調,對前面len-1個節點繼續進行對調整過程。
Build_MAX_Heap(heap)
for i in range(len(heap)-1,-1,-1):
heap[0],heap[i] = heap[i],heap[0]
MAX_Heapify(heap, i, 0)
return heap
if __name__ == '__main__':
a = [30,50,57,77,62,78,94,80,84]
print (a)
HeapSort(a)
print (a)
b = [random.randint(1,1000) for i in range(1000)]
print (b)
HeapSort(b)
print (b)