다익스트라(dijkstra) 알고리즘 파이썬 구현 코드

다익스트라 알고리즘 구현 코드 

import heapq

def dijkstra(graph, start):
    distances = { node : float('inf') for node in graph}
    distances[start] = 0
    queue = []
    heapq.heappush(queue, [start, distances[start]])
    
    while queue:
        now, now_dist = heapq.heappop(queue)
        
        if distances[now] < now_dist:
            continue
            
        for new, new_dist in graph[now]:
            distance = now_dist + new_dist
            if distance < distances[new]:
                distances[new] = distance
                heapq.heappush(queue, [new, distance])
    
    return distances

graph = {
    'A': {'B': 8, 'C': 1, 'D': 2},
    'B': {},
    'C': {'B': 5, 'D': 2},
    'D': {'E': 3, 'F': 5},
    'E': {'F': 1},
    'F': {'A': 5}
}

print(dijkstra(graph, 'A'))

 

 

실행 결과

{'A': 0, 'B': 6, 'C': 1, 'D': 2, 'E': 5, 'F': 6}

 

 

참조

https://justkode.kr/algorithm/python-dijkstra/

Python으로 다익스트라(dijkstra) 알고리즘 구현하기