def test_insert_raises_exception_when_heap_is_full():
def priority_function(item1, item2):
return item1 - item2
heap = Heap(0, priority_function)
with pytest.raises(Exception):
heap.insert(20)
def test_insert_grows_when_heap_is_full_and_length_not_0():
heap = Heap(1)
assert heap.size == 1
assert len(heap.items) == 1
heap.insert(20)
heap.insert(21)
assert heap.size == 2
assert len(heap.items) == 2
def test_insert_adds_value_to_heap():
def priority_function(item1, item2):
return item1 - item2
heap = Heap(5, priority_function)
heap.insert(1)
heap.insert(3)
assert heap.items[0] == 3
assert heap.items[1] == 1
def test_running_median_challenge():
sut = RunningMedian()
array = sut.parse_text_file(text)
min_heap = Heap(10, max_priority_function)
max_heap = Heap(10, min_priority_function)
sum = 0
for float_number in array:
sum += sut.running_median(min_heap, max_heap, float_number)
assert sum == pytest.approx(4995738.755804, .000001)
def test_delete_removes_target_item_from_heap():
heap = Heap(5)
heap.insert(1)
heap.insert(3)
heap.insert(2)
heap.insert(4)
heap.delete(3)
assert heap.get_size() == 3
assert heap.extract() == 4
assert heap.extract() == 2
def test_running_median_finds_running_median_along_way():
min_heap = Heap(10, max_priority_function)
max_heap = Heap(10, min_priority_function)
new_value = 4
sut = RunningMedian()
result = sut.running_median(min_heap, max_heap, new_value)
assert result == 4
result = sut.running_median(min_heap, max_heap, 6)
assert result == 5
result = sut.running_median(min_heap, max_heap, 10)
assert result == 6
def test_get_size_returns_size_of_heap():
heap = Heap(5, default_priority_function)
heap.insert(1)
heap.insert(5)
heap.insert(6)
heap.insert(2)
result = heap.get_size()
assert result == 4
heap.extract()
result = heap.get_size()
assert result == 3
def test_is_balanced_returns_false_when_heaps_off_by_more_than_one():
min_heap = Heap(5, max_priority_function)
max_heap = Heap(5, min_priority_function)
min_heap.insert(1)
min_heap.insert(3)
min_heap.insert(2)
max_heap.insert(6)
sut = RunningMedian()
result = sut.is_balanced(min_heap, max_heap)
assert result is False
def test_is_balanced_returns_true_when_heaps_odd_and_off_by_one():
min_heap = Heap(5, max_priority_function)
max_heap = Heap(5, min_priority_function)
min_heap.insert(1)
min_heap.insert(3)
min_heap.insert(2)
max_heap.insert(6)
max_heap.insert(7)
sut = RunningMedian()
result = sut.is_balanced(min_heap, max_heap)
assert result is True
def test_heap_behaves_correctly_with_duplicate_values():
heap = Heap(5, default_priority_function)
heap.insert(1)
heap.insert(5)
heap.insert(3)
heap.insert(5)
assert heap.extract() == 5
assert heap.extract() == 5
assert heap.extract() == 3
assert heap.peek() == 1
def test_running_media_with_sliding_window_behaves_appropriately_with_challenge(
):
sut = RunningMedian()
array = sut.parse_text_file(text)
min_heap = Heap(10, max_priority_function)
max_heap = Heap(10, min_priority_function)
sum = 0
window = []
for float_number in array:
sum += sut.running_median_with_sliding_window(min_heap, max_heap,
float_number, window,
100)
expected_result = 4995205.397700
assert sum == pytest.approx(expected_result, 0.0001)
def test_extract_returns_value_from_heap():
heap = Heap(5, default_priority_function)
heap.insert(1)
heap.insert(5)
heap.insert(6)
result = heap.extract()
assert result == 6
result = heap.extract()
assert result == 5
result = heap.extract()
assert result == 1
def test_heap_can_be_created_with_proper_parameters():
def priority_function(item1, item2):
return item1 - item2
result = Heap(5, priority_function)
assert result.size == 5
assert result.items == [None, None, None, None, None, None]
def test_peek_returns_highest_priority_value():
heap = Heap(5, default_priority_function)
heap.insert(1)
heap.insert(5)
heap.insert(6)
heap.insert(2)
result = heap.peek()
assert result == 6
def test_maintain_sliding_window_reduces_size_appropriately():
sut = RunningMedian()
array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
min_heap = Heap(10, max_priority_function)
max_heap = Heap(10, min_priority_function)
for i in range(5):
min_heap.insert(array[i])
max_heap.insert(array[i + 5])
sut.maintain_sliding_window(min_heap, max_heap, array, 11, 10)
assert array[0] == 2
assert len(array) == 10
assert array[-1] != 10
def test_heap_extract_returns_the_proper_number_when_it_is_the_last():
min_heap = Heap(10, max_priority_function)
min_heap.insert(1)
min_heap.insert(3)
min_heap.insert(2)
min_heap.insert(4)
result = min_heap.extract()
assert result == 4
def test_running_median_finds_running_median_with_heaps_set_up():
min_heap = Heap(10, max_priority_function)
min_heap.insert(3)
min_heap.insert(5)
max_heap = Heap(10, min_priority_function)
max_heap.insert(7)
max_heap.insert(9)
new_value = 4
sut = RunningMedian()
result = sut.running_median(min_heap, max_heap, new_value)
assert result == 5
result = sut.running_median(min_heap, max_heap, 6)
assert result == 5.5
result = sut.running_median(min_heap, max_heap, 10)
assert result == 6
def test_running_media_with_sliding_window_works_with_individual_additions():
min_heap = Heap(10, max_priority_function)
max_heap = Heap(10, min_priority_function)
window = []
new_value = 4
sut = RunningMedian()
result = sut.running_median_with_sliding_window(min_heap, max_heap,
new_value, window, 3)
assert result == 4
result = sut.running_median_with_sliding_window(min_heap, max_heap, 6,
window, 3)
assert result == 5
result = sut.running_median_with_sliding_window(min_heap, max_heap, 10,
window, 3)
assert result == 6
result = sut.running_median_with_sliding_window(min_heap, max_heap, 1,
window, 3)
assert result == 6
result = sut.running_median_with_sliding_window(min_heap, max_heap, 11,
window, 3)
assert result == 10
result = sut.running_median_with_sliding_window(min_heap, max_heap, 2,
window, 3)
assert result == 2
def test_extract_returns_value_from_heap():
def priority_function(item1, item2):
return item1 - item2
heap = Heap(5, priority_function)
heap.insert(1)
heap.insert(5)
heap.insert(6)
result = heap.extract()
# assert result == 5
print(heap.items)
# assert heap.items[0] == 1
# assert heap.items[1] is None
# insert things that are out of priority order and test the result
# assert the right values on each extract
# switch off between inserts and extracts in some tests
# Test duplicate priorities (insert(1)) (insert(1)) etc.
# Write a test with a bubble down with a full queue. This should move the item
# at the end
def test_balance_heaps_balanced_an_imbalanced_pair_of_heaps():
min_heap = Heap(10, max_priority_function)
max_heap = Heap(10, min_priority_function)
min_heap.insert(1)
min_heap.insert(3)
min_heap.insert(2)
min_heap.insert(4)
max_heap.insert(7)
max_heap.insert(5)
sut = RunningMedian()
sut.balance_heaps(min_heap, max_heap)
assert min_heap.get_size() == 3
assert max_heap.get_size() == 3
assert 4 in max_heap.items
assert 4 not in min_heap.items
def test_expand_doubles_the_size_of_the_heap():
heap = Heap(5)
heap.insert(1)
heap.expand()
assert heap.size == 10
assert len(heap.items) == 10
def test_extract_and_insert_alternating_returns_values():
heap = Heap(5, default_priority_function)
heap.insert(1)
heap.insert(5)
assert heap.extract() == 5
heap.insert(6)
heap.insert(2)
assert heap.extract() == 6
heap.insert(6)
assert heap.extract() == 6
heap.insert(10)
heap.insert(1)
assert heap.get_size() == 4
def test_insert_adds_value_to_heap():
heap = Heap(5)
heap.insert(1)
heap.insert(3)
assert heap.items[0] == 3
assert heap.items[1] == 1
def test_insert_adds_values_to_heap_out_of_order():
heap = Heap(5)
heap.insert(1)
heap.insert(3)
heap.insert(10)
heap.insert(6)
heap.insert(2)
assert heap.extract() == 10
assert heap.extract() == 6
assert heap.extract() == 3
assert heap.extract() == 2
assert heap.extract() == 1
def test_is_balanced_returns_true_with_balanced_heaps():
min_heap = Heap(5, max_priority_function)
max_heap = Heap(5, min_priority_function)
min_heap.insert(1)
min_heap.insert(3)
min_heap.insert(2)
max_heap.insert(6)
max_heap.insert(7)
max_heap.insert(5)
sut = RunningMedian()
result = sut.is_balanced(min_heap, max_heap)
assert result is True
def test_delete_raises_exception_if_value_not_present():
heap = Heap(5)
heap.insert(1)
with pytest.raises(Exception):
heap.delete(4)
def test_heap_can_be_created_with_proper_parameters():
result = Heap(5)
assert result.size == 5
assert result.items == [None, None, None, None, None]
