[백준] 1916번 최소비용 구하기 (파이썬)

https://www.acmicpc.net/problem/1916

import sys
import heapq

input = sys.stdin.readline

n = int(input())
m = int(input())
graph = [[] for _ in range(n+1)]
for _ in range(m):
    a, b, c = map(int, input().split())
    graph[a].append((b, c))
start, end = map(int, input().split())

INF = float('inf')
distance = [INF]*(n+1)

def dijkstra(start):
    q = [] 
    heapq.heappush(q, (0, start))
    distance[start] = 0
    
    while q:
        dist, now = heapq.heappop(q)
        if distance[now] < dist:
            continue
            
        for i in graph[now]:
            cost = dist + i[1]
            if cost < distance[i[0]]:
                distance[i[0]] = cost
                heapq.heappush(q, (cost, i[0]))
                
dijkstra(start)
print(distance[end])