def merge_k(lists):
# If lists is empty
if not len(lists):
return
# Initializing an array containing the first element of each list
data = [lst for lst in lists]
# Initializing a heap with the data
heap = Heap(data)
# Extracting min and storing reference to the head
result = heap.poll()
head = result
if result.next:
heap.insert(result.next)
# Extracting min and replacing with next one from list
while not heap.is_empty():
min_item = heap.poll()
result.next = min_item
result = result.next
if min_item.next:
heap.insert(min_item.next)
return head
def test_insert():
from heaps.heap import Heap
heap = Heap()
for i in range(10):
heap.insert(i)
assert len(heap.array) == 10
def test_insert():
heap = Heap([])
heap.insert(4)
heap.insert(3)
heap.insert(6)
heap.insert(1)
heap.insert(2)
heap.insert(0)
heap.insert(5)
assert_values(heap)
assert list(heap) == []
def test_delete():
from random import shuffle
from heaps.heap import Heap
MAX_DATA = 100000
heap = Heap()
data = [x for x in range(MAX_DATA)]
shuffle(data)
for datum in data:
heap.insert(datum)
result = []
for _ in range(MAX_DATA):
result.append(heap.delete())
data.sort(reverse=True)
assert result == data