Created
April 11, 2021 18:27
-
-
Save calthoff/c145b9aa39cb76c4c239015948a000c1 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import heapq | |
def dijkstra(graph, starting_vertex): | |
distances = {vertex: float('infinity') for vertex in graph} | |
distances[starting_vertex] = 0 | |
pq = [(0, starting_vertex)] | |
while len(pq) > 0: | |
current_distance, current_vertex = heapq.heappop(pq) | |
if current_distance > distances[current_vertex]: | |
continue | |
for neighbor, weight in graph[current_vertex].items(): | |
distance = current_distance + weight | |
if distance < distances[neighbor]: | |
distances[neighbor] = distance | |
heapq.heappush(pq, (distance, neighbor)) | |
return distances | |
graph = { | |
'U': {'V': 2, 'W': 5, 'X': 1}, | |
'V': {'U': 2, 'X': 2, 'W': 3}, | |
'W': {'V': 3, 'U': 5, 'X': 3, 'Y': 1, 'Z': 5}, | |
'X': {'U': 1, 'V': 2, 'W': 3, 'Y': 1}, | |
'Y': {'X': 1, 'W': 1, 'Z': 1}, | |
'Z': {'W': 5, 'Y': 1}, | |
} | |
print(dijkstra(graph, 'Z')) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment