def extract_max(S):
"Remove and return the element of S with largest key - O(lg n)"
if S.heap_size < 1:
raise Exception("Trivial heap")
max, S[0] = S[0], S[S.heap_size - 1]
S.heap_size -= 1
max_heapify(S, 0)
return max
def heap_extract_max(a):
if len(a) < 1:
return 'error: heap underflow'
max = a[0]
a[0] = a[len(a) - 1]
a.pop()
heap_sort.max_heapify(a, 0)
return max
def extract_max(heap):
if heap.heap_size < 1:
raise HeapUnderflowException
mx = heap.at(0)
lst = heap.heap_size - 1
heap.put(0, heap.at(lst))
heap.heap_size -= 1
del heap.array[lst] # not totally necessary
hs.max_heapify(heap, 0)
return mx
def extract_max(self): if self.heap_size()<1: raise "heap underflow" maxnum=self.queue[1] self.queue[1]=self.queue[self.heap_size()] self.queue.pop() # self.heap_size -= 1 heap_size=self.heap_size() max_heapify(self.queue,1,heap_size) return maxnum
def heap_extract_max(array, heap_size):
if heap_size < 1:
raise ValueError
max_value = array[0]
array[0] = array[heap_size - 1]
del array[heap_size - 1]
heap_size -= 1
max_heapify(array, heap_size, 0)
return max_value
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 delete(S, i):
"""
Deletes the item at node i. Delete is done in 2 steps:
1. Increase the element at i to infinity using increase_key(). This bring S[i] to the root of the max heap.
2. Replace the root with the last leaf in the heap. Decrement heap size by 1 and apply max_heapify()
This fixes the gap that is left in the subtree where S[i] is the root - O(lg n)
"""
increase_key(S, i, float("inf"))
S[0] = S[S.heap_size - 1]
S.heap_size -= 1
max_heapify(S, 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 runTest(self) :
heap_sort.max_heapify( self.values[ 0 ], 1, len( self.values[ 0 ] ))
self.assertEqual( self.values[ 0 ],
self.expected[ 0 ],
"not passed")
def test_not_max_heap_before(self):
self.array = [1,2,3]
self.assertEqual(heap_sort.max_heapify(self.array,0),[3,2,1])
def test_already_max_heap(self):
self.array = [3,2,1]
self.assertEqual(heap_sort.max_heapify(self.array,0),self.array)
def test_height2_not_max_heapify_before(self):
self.array = [5,3,9,2,1,4,6]
self.assertEqual(heap_sort.max_heapify(self.array,0),[9,3,6,2,1,4,5])
def test_max_heapify_for_even_count_of_nums(self):
self.assertEqual([3, 6, 5, 1, 0, 9], max_heapify([3, 1, 5, 6, 0, 9],
2))
def test_max_heapify_for_bigger_sample_with_inner_pos(self):
nums = [16, 4, 10, 14, 7, 9, 3, 2, 8, 1]
self.assertEqual(nums, max_heapify(nums, 4))
def test_max_heapify_for_bigger_sample(self):
nums = [16, 4, 10, 14, 7, 9, 3, 2, 8, 1]
self.assertEqual([16, 14, 10, 8, 7, 9, 3, 2, 4, 1],
max_heapify(nums, 2))
