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heap_structure.py
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heap_structure.py
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class Heap(object):
HEAP_SIZE = 10;
def __init__(self):
self.heap = [0]*Heap.HEAP_SIZE
self.currentPosition = -1
def insert(self, item):
# if heap is full , we print a notification
if self.isFull():
print("Heap is full")
return
# else, increment the currentPosition and add item
self.currentPosition+=1
self.heap[self.currentPosition] = item
self.fixUp(self.currentPosition)
def fixUp(self, index):
parentIndex = int((index-1)/2)
while parentIndex >=0 and self.heap[parentIndex] < self.heap[index]:
# if True swap heap[index] and heap[parentIndex]
temp = self.heap[index]
self.heap[index] = self.heap[parentIndex]
self.heap[parentIndex] = temp
# update the index and parentIndex
index = parentIndex
parentIndex = int((index-1)/2)
def fixDown(self, index, upto):
if upto < 0:
upto = self.currentPosition
while index<=upto:
leftChild = 2*index+1
rightChild = 2*index+2
if leftChild <= upto:
childToSwap = 0
else:
if self.heap[leftChild] < self.heap[rightChild]:
childToSwap = leftChild
else:
childToSwap = rightChild
if self.heap[index] < self.heap[childToSwap]:
temp = self.heap[index]
self.heap[index] = self.heap[childToSwap]
self.heap[childToSwap] = temp
else:
break
index = childToSwap
else:
return
def heapSort(self):
for i in range(0, self.currentPosition+1):
temp = self.heap[0]
print("%d"%temp)
self.heap[0] = self.heap[self.currentPosition-i]
self.heap[self.currentPosition-i] = temp
self.fixDown(0, self.currentPosition-i-1)
def getMax():
result = self.heap[0]
self.currentPosition-=1
self.heap[0] = self.heap[self.currentPosition]
del self.heap[self.currentPosition]
self.fixDown(0, -1)
return result
def isFull(self):
return self.currentPosition == Heap.HEAP_SIZE
some_heap=Heap()
some_heap.insert(12)
some_heap.insert(-3)
some_heap.insert(21)
some_heap.insert(7)
some_heap.insert(4)
some_heap.heapSort()