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Abigail C. - Rock#36

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@ChaAbby ChaAbby commented Jan 18, 2022

Heaps Practice

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Comprehension Questions

Question Answer
How is a Heap different from a Binary Search Tree?
Could you build a heap with linked nodes?
Why is adding a node to a heap an O(log n) operation?
Were the heap_up & heap_down methods useful? Why?

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Really well done Abigail, you hit the learning goals here.

Comment thread heaps/heap_sort.py
Comment on lines 3 to +6
def heap_sort(list):
""" This method uses a heap to sort an array.
Time Complexity: ?
Space Complexity: ?
Time Complexity: O(n log n)
Space Complexity: O(1)
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👍 However the space complexity is O(n) because you are building up a heap of n nodes as the function runs.

Comment thread heaps/min_heap.py
Comment on lines +28 to +33
if value == None:
value = key

node = HeapNode(key,value)
self.store.append(node)
self.heap_up(len(self.store) -1)
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👍 Space/time complexity?

Comment thread heaps/min_heap.py
Comment on lines 35 to +46
def remove(self):
""" This method removes and returns an element from the heap
maintaining the heap structure
Time Complexity: ?
Time Complexity: O(log n)
Space Complexity: ?
"""
pass
if len(self.store) == 0:
return None

self.swap(0, len(self.store) -1)
min = self.store.pop()
self.heap_down(0)
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👍 Space complexity?

Comment thread heaps/min_heap.py
Space complexity: ?
"""
pass
return self.store == []
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👍

Comment thread heaps/min_heap.py
return self.store == []


def heap_up(self, index):
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👍 Space/time complexity?

Comment thread heaps/min_heap.py
Comment on lines 90 to 95
def heap_down(self, index):
""" This helper method takes an index and
moves the corresponding element down the heap if it's
larger than either of its children and continues until
the heap property is reestablished.
"""
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👍 Nice work, very compact

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