[백준-5972] 택배 배송 / Python

5972번: 택배 배송

import sys
import heapq

input = sys.stdin.readline
INF = int(1e9)

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

print(distance[-1])

 

해설

최단경로 알고리즘(다익스트라)으로 해결할 수 있었던 문제였다.