def dijkstra_min_heap(self, src):
"""
Dijkstra's using a priority queue, more specifically
a Binary heap.
Time complexity: O((|E| + |V|)logV)
"""
if self.vertices == 0:
return []
heap = BinaryHeap()
dist = [float("inf")] * self.vertices
tuple = (0, src)
heap.insert(tuple)
dist[src] = 0
while heap.currentSize > 0:
u = heap.remove_min()
curWeight = u[0]
curNode = u[1]
# go over all vertices adjacent to u
for v in range(self.vertices):
if (self.graph[curNode][v] > 0
and dist[v] > dist[curNode] + self.graph[curNode][v]):
dist[v] = dist[curNode] + self.graph[curNode][v]
heap.insert((dist[v], v))
return dist
class TestBinaryHeap(unittest.TestCase):
"""
Test suite for the binary_heap data structures
"""
def setUp(self):
self.min_heap = BinaryHeap()
self.min_heap.insert(4)
self.min_heap.insert(50)
self.min_heap.insert(7)
self.min_heap.insert(55)
self.min_heap.insert(90)
self.min_heap.insert(87)
def test_insert(self):
# Before insert 2: [0, 4, 50, 7, 55, 90, 87]
# After insert: [0, 2, 50, 4, 55, 90, 87, 7]
self.min_heap.insert(2)
self.assertEqual([0, 2, 50, 4, 55, 90, 87, 7], self.min_heap.heap)
self.assertEqual(7, self.min_heap.currentSize)
def test_remove_min(self):
ret = self.min_heap.remove_min()
# Before remove_min : [0, 4, 50, 7, 55, 90, 87]
# After remove_min: [7, 50, 87, 55, 90]
# Test return value
self.assertEqual(4, ret)
self.assertEqual([0, 7, 50, 87, 55, 90], self.min_heap.heap)
self.assertEqual(5, self.min_heap.currentSize)
class TestBinaryHeap(unittest.TestCase):
"""
Test suite for the binary_heap data structures
"""
def setUp(self):
self.min_heap = BinaryHeap()
self.min_heap.insert(4)
self.min_heap.insert(50)
self.min_heap.insert(7)
self.min_heap.insert(55)
self.min_heap.insert(90)
self.min_heap.insert(87)
def test_insert(self):
# Before insert 2: [0, 4, 50, 7, 55, 90, 87]
# After insert: [0, 2, 50, 4, 55, 90, 87, 7]
self.min_heap.insert(2)
self.assertEqual([0, 2, 50, 4, 55, 90, 87, 7],
self.min_heap.heap)
self.assertEqual(7, self.min_heap.currentSize)
def test_remove_min(self):
ret = self.min_heap.remove_min()
# Before remove_min : [0, 4, 50, 7, 55, 90, 87]
# After remove_min: [7, 50, 87, 55, 90]
# Test return value
self.assertEqual(4,ret)
self.assertEqual([0, 7, 50, 87, 55, 90],
self.min_heap.heap)
self.assertEqual(5, self.min_heap.currentSize)