def test_greater_child_index_one(self):
"""
The 'greater child index' of an element without children is None.
"""
h = MaxHeap()
h._data.append('fake')
self.assertIsNone(h._greater_child_index(0))
def test_greater_child_index_left_only(self):
"""
The 'greater child index' of an element with just a left child (no right
child) returns the index of that left child.
"""
h = MaxHeap()
h._data.append('fake')
h._data.append('fake')
self.assertEqual(1, h._greater_child_index(0))
def test_greater_child_index_left(self):
"""
The 'greater child index' of an element with a left and right child, is
the index of the left child when it has a value greater than or equal to
the right child.
"""
h = MaxHeap()
h._data.append(10)
h._data.append(5)
h._data.append(1)
self.assertEqual(1, h._greater_child_index(0))
def test_greater_child_index_right(self):
"""
The 'greater child index' of an element with a left and right child, is
the index of the right child when it has a larger value than the left child.
Hint: Refine your logic. What are the possible states? No children, a
left but no right, or a left and a right.
"""
h = MaxHeap()
h._data.append(10)
h._data.append(1)
h._data.append(5)
self.assertEqual(2, h._greater_child_index(0))
