백준 5972. 택배 배송

https://www.acmicpc.net/problem/5972

import sys, heapq
input = sys.stdin.readline

n, m = map(int,input().split())
links = [[] for _ in range(n+1)]
dist = [float('inf')] * (n+1)

for _ in range(m):
    s, e, cost = map(int,input().split())
    links[s].append((e, cost))
    links[e].append((s, cost))

def d(start):
    q = []
    heapq.heappush(q,(0,start))
    dist[start] = 0

    while q:
        cost, node = heapq.heappop(q)

        if cost > dist[node]:
            continue

        for nxt, w in links[node]:
            if dist[node] + w < dist[nxt]:
                dist[nxt] = dist[node] + w
                heapq.heappush(q,(dist[nxt],nxt))
d(1)

print(dist[n])