def main():
a = [16, 14, 10, 8, 7, 9, 3, 2, 4, 1]
heap_sort.build_max_heap(a)
print(heap_maximum(a)) #print maximum element from heap
print(heap_extract_max(a)) #extract the maximum element from the heap
max_heap_insert(a, 20) #insert new element in the heap
print(a)
def heap_increase_key(arr, i, key):
build_max_heap(arr)
if key < arr[i]:
print('New key is smaller then current key')
arr[i] = key
while i > 0 and arr[parent(i)] < arr[i]:
arr[i], arr[parent(i)] = arr[parent(i)], arr[i]
i = parent(i)
def heap_extract_max(arr):
n = len(arr)
build_max_heap(arr)
#print n
if n < 0:
return 'Heap Underflow'
max = arr[0]
arr.remove(max)
n = len(arr)
max_heapify(arr, n, 0)
return max
def heap_maximum(arr):
build_max_heap(arr)
return arr[0]
def max_heap_insert(arr, key):
build_max_heap(arr)
n = len(arr)
arr.append(-9999999)
heap_increase_key(arr, n, key)
# Increase key in Heap
def heap_increase_key(arr, i, key):
build_max_heap(arr)
if key < arr[i]:
print('New key is smaller then current key')
arr[i] = key
while i > 0 and arr[parent(i)] < arr[i]:
arr[i], arr[parent(i)] = arr[parent(i)], arr[i]
i = parent(i)
# Insert element to max heap
def max_heap_insert(arr, key):
build_max_heap(arr)
n = len(arr)
arr.append(-9999999)
heap_increase_key(arr, n, key)
# arr = [4, 1, 3, 2, 16, 9, 10, 14, 11, 13, 8, 12, 15, 7]
arr = [15, 13, 9, 5, 12, 8, 7, 4, 0, 6, 2, 1]
# for i in range(len(arr)-1):
# max_val = heap_extract_max(arr)
# print(max_val)
build_max_heap(arr)
print(arr)
#heap_increase_key(arr, 8, 15)
max_heap_insert(arr, 10)
print(arr)
def test_as_my_wish(self):
self.test_value = [1,2,3,45,6,7,100]
after_run = heap_sort.build_max_heap(self.test_value)
self.assertEqual(after_run,[100,45,7,2,6,1,3])
def test_range(self):
self.test_value = range(100,0,-1)
self.assertEqual(heap_sort.build_max_heap(self.test_value)[0],100)
from heap_sort import build_max_heap,max_heapify
"""
A Priority Queue is a data structure for maintaining a set S of elements, each with an associated value called a key.
A max-priority queue supports the following operations:
INSERT(S,x)
MAXIMUM(S)
EXTRACT-MAX(S): pop the maximum elements.
INCREASE-KEY(S,x,k) : increase the value of elements x's key to the new value k,
which is assumed to be at least as large as x's current key value.
"""
test = [4,1,3,2,16,9,10,14,8,7]
test = build_max_heap(test)
# A must be a max heap.
def maximum(A):
return A[0]
def extract_max(A):
if len(A) < 1:
return []
max = A[0]
A[1] = A[-1]
A = A[:-1]
A = max_heapify(A,0)
return max,A
def increase_key(A,x,key):
if key < A[x]:
raise SyntaxError,'new key is smalller than current key'
A[x] = key
while x > 0 and A[(x+1)/2-1] < A[x]:
def __init__(self,a): build_max_heap(a) self.queue=a
def test_build_max_heap_for_given_sample(self):
actual = build_max_heap([1, 2, 0, 8, 9, 3, 5, 4, 7, 6])
expected = [9, 8, 5, 7, 6, 3, 0, 4, 1, 2]
self.assertListEqual(expected, actual)
def test_build_max_heap_given_even_count_of_nums(self):
actual = build_max_heap([16, 4, 10, 14, 7, 9, 3, 2, 8, 1])
expected = [16, 14, 10, 8, 7, 9, 3, 2, 4, 1]
self.assertListEqual(expected, actual)
def test_build_max_heap_given_odd_count_of_nums(self):
actual = build_max_heap([3, 5, 1, 6, 0])
expected = [6, 5, 1, 3, 0]
self.assertListEqual(expected, actual)
