def test_remove_removes_first_occurence_of_value_in_array(self):
da = DynamicArray()
da._n = 5
da._capacity = 5
da._A = da._make_array(da._capacity)
da._A[0:5] = ['foo', 'bar', 'spam', 'baz', 'spam']
expected_elements = ['foo', 'bar', 'baz', 'spam']
da.remove('spam')
self.assertEqual(da._A[0:4], expected_elements)
self.assertEqual(da._n, 4)
def test_remove_halves_array_capacity_if_less_than_quarter_of_capacity_used(
self):
da = DynamicArray()
da._capacity = 64
da._n = 17
da._A = da._make_array(da._capacity)
da._A[0:17] = [l for l in 'abcdefghijklmnopq']
# first remove() should not shrink the array, since with 16 elements
# we have not passed the N/4 threshold.
da.remove('a')
self.assertEqual(da._capacity, 64)
# second remove() should trigger halving the array capacity:
da.remove('q')
self.assertEqual(da._capacity, 32)