Python Heap Sort
Python3 ExamplesHeapsort is a sorting algorithm designed using the heap data structure. A heap is a structure that approximates a complete binary tree, and at the same time satisfies the heap property: that is, the key or index of a child node is always less than (or greater than) its parent. Heapsort can be said to be a selection sort that uses the concept of a heap to sort.
Example
def heapify(arr, n, i):
largest = i
l = 2 * i + 1 # left = 2*i + 1
r = 2 * i + 2 # right = 2*i + 2
if l < n and arr[i] < arr[l]:
largest = l
if r < n and arr[largest] < arr[r]:
largest = r
if largest != i:
arr[i],arr[largest] = arr[largest],arr[i] # Swap
heapify(arr, n, largest)
def heapSort(arr):
n = len(arr)
# Build a maxheap.
for i in range(n, -1, -1):
heapify(arr, n, i)
# Swap elements one by one
for i in range(n-1, 0, -1):
arr[i], arr[0] = arr[0], arr[i] # Swap
heapify(arr, i, 0)
arr = [ 12, 11, 13, 5, 6, 7]
heapSort(arr)
n = len(arr)
print ("After sorting")
for i in range(n):
print ("%d" %arr[i]),
The output of executing the above code is:
排序后 5 6 7 11 12 13Other Extensions