[DK]백준 - 최소비용 구하기(1916) - Python

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

1916번: 최소비용 구하기

 

다익스트라 알고리즘을 사용하는 기본적인 문제이다.

 

import heapq
import sys
input = sys.stdin.readline

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

def dijkstra(adj, n, start, end):
    heap = []
    heapq.heappush(heap, [0, start])
    INF = float('inf')
    dist = [INF] * (n + 1)
    dist[start] = 0

    while heap:
        cost, node = heapq.heappop(heap)
        if cost > dist[node]:
            continue
        for C, N in adj[node]:
            C += cost
            if C < dist[N]:
                dist[N] = C
                heapq.heappush(heap, [C, N])

    return dist[end]

print(dijkstra(adj, n, start, end))