def test_delete_min():
node1 = Node(34)
node2 = Node(10)
node3 = Node(12)
node4 = Node(20)
heap = BinomialHeap()
heap.insert(node1)
heap.insert(node2)
heap.insert(node3)
heap.insert(node4)
assert heap.find_min() == node2
assert heap.num_elements() == 4
assert heap.delete_min() == node2
assert heap.find_min() == node3
assert heap.num_elements() == 3
assert heap.delete_min() == node3
assert heap.num_elements() == 2
assert heap.find_min() == node4
assert heap.delete_min() == node4
assert heap.find_min() == node1
assert heap.delete_min() == node1
assert heap.find_min() is None
assert heap.num_elements() == 0
def test_merge():
node1 = Node(34)
node2 = Node(10)
node3 = Node(12)
node4 = Node(20)
heap1 = BinomialHeap()
heap1.insert(node1)
heap1.insert(node2)
heap1.insert(node3)
heap1.insert(node4)
assert heap1.find_min() == node2
assert heap1.num_elements() == 4
node5 = Node(3)
node6 = Node(11)
node7 = Node(14)
node8 = Node(20)
heap2 = BinomialHeap()
heap2.insert(node5)
heap2.insert(node6)
heap2.insert(node7)
heap2.insert(node8)
assert heap2.find_min() == node5
heap1.merge(heap2)
assert heap1.find_min() == node5
assert heap1.num_elements() == 8
b = heap1.delete_min()
assert b == node5
assert heap1.find_min() == node2
def test_insert():
heap = BinomialHeap()
assert heap.num_elements() == 0
new_node1 = Node(2)
heap.insert(new_node1)
assert heap.num_elements() == 1
assert new_node1.right_sibling == new_node1
assert new_node1.right_sibling == new_node1
new_node2 = Node(3)
heap.insert(new_node2)
assert heap.num_elements() == 2
assert new_node1.right_sibling == new_node2
assert new_node1.left_sibling == new_node2
assert new_node2.right_sibling == new_node1
assert new_node2.left_sibling == new_node1
# min_root now new node3 = 1
new_node3 = Node(1)
heap.insert(new_node3)
assert heap.num_elements() == 3
assert new_node3.right_sibling == new_node2
assert new_node3.left_sibling == new_node1
assert new_node3.right_sibling == new_node2
assert new_node2.left_sibling == new_node3
assert new_node1.right_sibling == new_node3
assert new_node1.left_sibling == new_node2
def test_decrease_key():
node1 = Node(34)
node2 = Node(10)
node3 = Node(12)
node4 = Node(20)
heap = BinomialHeap()
heap.insert(node1)
heap.insert(node2)
heap.insert(node3)
heap.insert(node4)
assert heap.num_elements() == 4
assert heap.find_min() == node2
pytest.raises(ValueError, heap.decrease_key, node3, 13)
pytest.raises(ValueError, heap.decrease_key, None, 13)
heap.decrease_key(node3, 11)
assert node3.key == 11
assert heap.find_min() == node2
heap.decrease_key(node3, 8)
assert heap.find_min() == node3
assert heap.find_min().key == 8
def test_find_min():
heap = BinomialHeap()
assert heap.find_min() is None
# min_root new_node1 = 2
new_node1 = Node(2)
heap.insert(new_node1)
min_root = heap.find_min()
assert new_node1 == min_root
new_node2 = Node(3)
heap.insert(new_node2)
min_root = heap.find_min()
# min_root still new_node1 = 2
assert min_root == new_node1
new_node3 = Node(1)
heap.insert(new_node3)
min_root = heap.find_min()
# min_root now new node3 = 1
assert min_root == new_node3