dijkstra template

Author: thomasgy422

Template/Graph/dijkstra.py

@@ -0,0 +1,34 @@
+ 
+import heapq
+class Solution:
+
+ def dijkstra(n: int, graph: list[list]):
+
+ starting_node = 0
+ distances = {node: float('inf') for node in range(n)}
+ distances[starting_node] = 0
+ 
+ pq = [(0, starting_node)]
+
+ while len(pq) > 0:
+
+ current_distance, current_node = heapq.heappop(pq)
+
+ if current_distance > distances[current_node]:
+ continue
+
+ for neighbor, weight in graph[current_node]:
+ distance = current_distance + weight
+ # Only consider this new path if it's better than any path we've
+ # already found.
+ if distance < distances[neighbor]:
+ distances[neighbor] = distance
+ heapq.heappush(pq, (distance, neighbor))
+
+ return distances
+
+
+n = 3
+graph = {0: [(1, 2), (2, 4)], 1: [(0, 2), (2, 1)], 2: [(1, 1), (0, 4)]}
+print(Solution.dijkstra(n, graph))
+