[백준] 1753번 최단경로 (파이썬)

https://www.acmicpc.net/problem/1753

import sys
import heapq

input = sys.stdin.readline

v, e = map(int, input().split())
k = int(input())
graph = [[] for _ in range(v+1)]
for _ in range(e):
    a, b, c = map(int, input().split())
    graph[a].append((b, c))
    
INF = float('inf')
distance = [INF]*(v+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(k)
for i in range(1, v+1):
    if distance[i] == INF:
        print('INF')
    else:
        print(distance[i])