def test_left_child_none(self):
"""
If the 'left child index' of an element at index i exceeds the bounds of
the data list, just return None.
Hint: Draw both a 5-element array and tree. What is the value of the left
child of the third (index 2) element? And the fourth? And the fifth?
"""
h = MaxHeap()
h._data.append('fake')
h._data.append('fake')
h._data.append('fake')
self.assertIsNone(h._left_child(1))
self.assertIsNone(h._left_child(2))
h._data.append('fake')
h._data.append('fake')
self.assertIsNone(h._left_child(2))
self.assertIsNone(h._left_child(3))
self.assertIsNone(h._left_child(4))
def test_left_child(self):
"""
Given an index i, the left child is the value at the 'left child index'
of i.
Hint: The phrase above is nearly identical to the code, if you use your
abstractions.
"""
h = MaxHeap()
fake_root = fake_value()
fake_left_child = fake_value()
fake_right_child = fake_value()
fake_left_left_child = fake_value()
fake_left_right_child = fake_value()
h._data.append(fake_root)
h._data.append(fake_left_child)
h._data.append(fake_right_child)
h._data.append(fake_left_left_child)
h._data.append(fake_left_right_child)
self.assertEqual(fake_left_child, h._left_child(0))
self.assertEqual(fake_left_left_child, h._left_child(1))
self.assertIsNone(h._left_child(2))
self.assertIsNone(h._left_child(3))
self.assertIsNone(h._left_child(4))
