def test_find_min_returns_the_minimum_data(self):
minimum = 0
heap = MinHeap()
heap.insert(42)
heap.insert(minimum)
heap.insert(1)
self.assertEqual(heap.find_min(), minimum)
def test_size_decrements_on_extract_min(self):
heap = MinHeap()
heap.insert(1)
heap.insert(2)
self.assertEqual(heap.size, 2)
heap.extract_min()
self.assertEqual(heap.size, 1)
heap.extract_min()
self.assertEqual(heap.size, 0)
def test_size_increments_on_insertion(self):
heap = MinHeap()
self.assertEqual(heap.size, 0)
heap.insert(12)
self.assertEqual(heap.size, 1)
heap.insert(42)
self.assertEqual(heap.size, 2)
def test_insert_preserves_heap_order(self):
heap = MinHeap()
heap.insert(4) # 4
heap.insert(5) # 4 5
heap.insert(3) # 3 5 4
heap.insert(2) # 2 3 4 5
self.assertEqual(heap._store[1], 2)
self.assertEqual(heap._store[2], 3)
self.assertEqual(heap._store[3], 4)
self.assertEqual(heap._store[4], 5)
def test_insert_appends_data(self):
data = 3
heap = MinHeap()
heap.insert(data)
self.assertEqual(heap._store[1], data)
def test_extract_min_maintains_the_heap_order(self):
heap = MinHeap()
heap.insert(1)
heap.insert(2)
heap.insert(3)
heap.insert(4)
heap.insert(5)
self.assertEqual(heap.extract_min(), 1)
self.assertEqual(heap.find_min(), 2)
self.assertEqual(heap.extract_min(), 2)
self.assertEqual(heap.find_min(), 3)
def test_extract_min_raises_IndexError_when_heap_is_empty(self):
with self.assertRaises(IndexError):
MinHeap().extract_min()