[백준] 5972번 택배 배송 파이썬 코드

코드

import sys, heapq
input = sys.stdin.readline
INF = 987654321

n,m = map(int, input().split())
graph = [[] for _ in range(n+1)]
visited = [INF]*(n+1)

for _ in range(m):
  a,b,c = map(int, input().split())
  graph[a].append((b,c))
  graph[b].append((a,c))

def dijkstra():
  queue = [(0,1)]
  visited[1] = 0
  while queue:
    cost, vertex = heapq.heappop(queue)
    if cost > visited[vertex]: continue
    for ver in graph[vertex]:
      ncost = cost + ver[1]
      if visited[ver[0]]>ncost:
        visited[ver[0]] = ncost
        heapq.heappush(queue, (ncost,ver[0]))
  return visited[n]
print(dijkstra())

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