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heap_sort.py
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heap_sort.py
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def max_heap_sort(arr, simulation=False):
""" Heap Sort that uses a max heap to sort an array in ascending order
Complexity: O(n log(n))
"""
iteration = 0
if simulation:
print("iteration",iteration,":",*arr)
for i in range(len(arr) - 1, 0, -1):
iteration = max_heapify(arr, i, simulation, iteration)
if simulation:
iteration = iteration + 1
print("iteration",iteration,":",*arr)
return arr
def max_heapify(arr, end, simulation, iteration):
""" Max heapify helper for max_heap_sort
"""
last_parent = (end - 1) // 2
# Iterate from last parent to first
for parent in range(last_parent, -1, -1):
current_parent = parent
# Iterate from current_parent to last_parent
while current_parent <= last_parent:
# Find greatest child of current_parent
child = 2 * current_parent + 1
if child + 1 <= end and arr[child] < arr[child + 1]:
child = child + 1
# Swap if child is greater than parent
if arr[child] > arr[current_parent]:
arr[current_parent], arr[child] = arr[child], arr[current_parent]
current_parent = child
if simulation:
iteration = iteration + 1
print("iteration",iteration,":",*arr)
# If no swap occurred, no need to keep iterating
else:
break
arr[0], arr[end] = arr[end], arr[0]
return iteration
def min_heap_sort(arr, simulation=False):
""" Heap Sort that uses a min heap to sort an array in ascending order
Complexity: O(n log(n))
"""
iteration = 0
if simulation:
print("iteration",iteration,":",*arr)
for i in range(0, len(arr) - 1):
iteration = min_heapify(arr, i, simulation, iteration)
return arr
def min_heapify(arr, start, simulation, iteration):
""" Min heapify helper for min_heap_sort
"""
# Offset last_parent by the start (last_parent calculated as if start index was 0)
# All array accesses need to be offset by start
end = len(arr) - 1
last_parent = (end - start - 1) // 2
# Iterate from last parent to first
for parent in range(last_parent, -1, -1):
current_parent = parent
# Iterate from current_parent to last_parent
while current_parent <= last_parent:
# Find lesser child of current_parent
child = 2 * current_parent + 1
if child + 1 <= end - start and arr[child + start] > arr[
child + 1 + start]:
child = child + 1
# Swap if child is less than parent
if arr[child + start] < arr[current_parent + start]:
arr[current_parent + start], arr[child + start] = \
arr[child + start], arr[current_parent + start]
current_parent = child
if simulation:
iteration = iteration + 1
print("iteration",iteration,":",*arr)
# If no swap occurred, no need to keep iterating
else:
break
return iteration