mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-24 13:31:07 +00:00
9b95e4f662
* Upgrade to Python 3.8 syntax
* updating DIRECTORY.md
Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
136 lines
3.4 KiB
Python
136 lines
3.4 KiB
Python
#!/usr/bin/python3
|
|
|
|
|
|
class Heap:
|
|
"""
|
|
>>> unsorted = [103, 9, 1, 7, 11, 15, 25, 201, 209, 107, 5]
|
|
>>> h = Heap()
|
|
>>> h.build_heap(unsorted)
|
|
>>> h.display()
|
|
[209, 201, 25, 103, 107, 15, 1, 9, 7, 11, 5]
|
|
>>>
|
|
>>> h.get_max()
|
|
209
|
|
>>> h.display()
|
|
[201, 107, 25, 103, 11, 15, 1, 9, 7, 5]
|
|
>>>
|
|
>>> h.insert(100)
|
|
>>> h.display()
|
|
[201, 107, 25, 103, 100, 15, 1, 9, 7, 5, 11]
|
|
>>>
|
|
>>> h.heap_sort()
|
|
>>> h.display()
|
|
[1, 5, 7, 9, 11, 15, 25, 100, 103, 107, 201]
|
|
>>>
|
|
"""
|
|
|
|
def __init__(self):
|
|
self.h = []
|
|
self.curr_size = 0
|
|
|
|
def get_left_child_index(self, i):
|
|
left_child_index = 2 * i + 1
|
|
if left_child_index < self.curr_size:
|
|
return left_child_index
|
|
return None
|
|
|
|
def get_right_child(self, i):
|
|
right_child_index = 2 * i + 2
|
|
if right_child_index < self.curr_size:
|
|
return right_child_index
|
|
return None
|
|
|
|
def max_heapify(self, index):
|
|
if index < self.curr_size:
|
|
largest = index
|
|
lc = self.get_left_child_index(index)
|
|
rc = self.get_right_child(index)
|
|
if lc is not None and self.h[lc] > self.h[largest]:
|
|
largest = lc
|
|
if rc is not None and self.h[rc] > self.h[largest]:
|
|
largest = rc
|
|
if largest != index:
|
|
self.h[largest], self.h[index] = self.h[index], self.h[largest]
|
|
self.max_heapify(largest)
|
|
|
|
def build_heap(self, collection):
|
|
self.curr_size = len(collection)
|
|
self.h = list(collection)
|
|
if self.curr_size <= 1:
|
|
return
|
|
for i in range(self.curr_size // 2 - 1, -1, -1):
|
|
self.max_heapify(i)
|
|
|
|
def get_max(self):
|
|
if self.curr_size >= 2:
|
|
me = self.h[0]
|
|
self.h[0] = self.h.pop(-1)
|
|
self.curr_size -= 1
|
|
self.max_heapify(0)
|
|
return me
|
|
elif self.curr_size == 1:
|
|
self.curr_size -= 1
|
|
return self.h.pop(-1)
|
|
return None
|
|
|
|
def heap_sort(self):
|
|
size = self.curr_size
|
|
for j in range(size - 1, 0, -1):
|
|
self.h[0], self.h[j] = self.h[j], self.h[0]
|
|
self.curr_size -= 1
|
|
self.max_heapify(0)
|
|
self.curr_size = size
|
|
|
|
def insert(self, data):
|
|
self.h.append(data)
|
|
curr = (self.curr_size - 1) // 2
|
|
self.curr_size += 1
|
|
while curr >= 0:
|
|
self.max_heapify(curr)
|
|
curr = (curr - 1) // 2
|
|
|
|
def display(self):
|
|
print(self.h)
|
|
|
|
|
|
def main():
|
|
for unsorted in [
|
|
[],
|
|
[0],
|
|
[2],
|
|
[3, 5],
|
|
[5, 3],
|
|
[5, 5],
|
|
[0, 0, 0, 0],
|
|
[1, 1, 1, 1],
|
|
[2, 2, 3, 5],
|
|
[0, 2, 2, 3, 5],
|
|
[2, 5, 3, 0, 2, 3, 0, 3],
|
|
[6, 1, 2, 7, 9, 3, 4, 5, 10, 8],
|
|
[103, 9, 1, 7, 11, 15, 25, 201, 209, 107, 5],
|
|
[-45, -2, -5],
|
|
]:
|
|
print("source unsorted list: %s" % unsorted)
|
|
|
|
h = Heap()
|
|
h.build_heap(unsorted)
|
|
print("after build heap: ", end=" ")
|
|
h.display()
|
|
|
|
print("max value: %s" % h.get_max())
|
|
print("delete max value: ", end=" ")
|
|
h.display()
|
|
|
|
h.insert(100)
|
|
print("after insert new value 100: ", end=" ")
|
|
h.display()
|
|
|
|
h.heap_sort()
|
|
print("heap sort: ", end=" ")
|
|
h.display()
|
|
print()
|
|
|
|
|
|
if __name__ == "__main__":
|
|
main()
|