fixed heap_sort

This commit is contained in:
Harshil Darji 2016-08-17 17:18:11 +05:30
parent f18d6dd92a
commit ca78a8a9af

View File

@ -1,4 +1,4 @@
"""
'''
This is a pure python implementation of the heap sort algorithm.
For doctests run following command:
@ -8,26 +8,27 @@ python3 -m doctest -v heap_sort.py
For manual testing run:
python insertion_sort.py
"""
from __future__ import print_function
'''
from __future__ import print_function
def heapify(unsorted,index,heap_size):
largest = index
left_index = 2*index + 1
right_index = 2*index + 2
if left_index < heap_size and unsorted[left_index] > unsorted[largest]:
largest = left_index
if right_index < heap_size and unsorted[right_index] > unsorted[largest]:
largest = right_index
def heapify(unsorted, index, heap_size):
largest = index
left_index = 2 * index + 1
right_index = 2 * index + 2
if left_index < heap_size and unsorted[left_index] > unsorted[largest]:
largest = left_index
if largest != index:
unsorted[largest],unsorted[index] = unsorted[index],unsorted[largest]
heapify(unsorted,largest,heap_size)
def heap_sort(unsorted):
"""Pure implementation of the heap sort algorithm in Python
if right_index < heap_size and unsorted[right_index] > unsorted[largest]:
largest = right_index
if largest != index:
unsorted[largest], unsorted[index] = unsorted[index], unsorted[largest]
heapify(unsorted, largest, heap_size)
def heap_sort(unsorted):
'''
Pure implementation of the heap sort algorithm in Python
:param collection: some mutable ordered collection with heterogeneous
comparable items inside
:return: the same collection ordered by ascending
@ -41,16 +42,15 @@ def heap_sort(unsorted):
>>> heap_sort([-2, -5, -45])
[-45, -5, -2]
"""
n=len(unsorted)
for i in range (n/2 - 1 , -1, -1):
heapify(unsorted,i,n)
for i in range(n - 1, -1, -1):
unsorted[0], unsorted[i] = unsorted[i], unsorted[0]
heapify(unsorted,0,i)
'''
n = len(unsorted)
for i in range(n//2 - 1, -1, -1):
heapify(unsorted, i, n)
for i in range(n - 1, -1, -1):
unsorted[0], unsorted[i] = unsorted[i], unsorted[0]
heapify(unsorted, 0, i)
return unsorted
if __name__ == '__main__':
import sys
if sys.version_info.major < 3:
@ -60,4 +60,4 @@ if __name__ == '__main__':
user_input = input_function('Enter numbers separated by a comma:\n')
unsorted = [int(item) for item in user_input.split(',')]
print (heap_sort(unsorted))
print(heap_sort(unsorted))