[프로그래머스] 여행경로 (Python)

link 🔗 https://programmers.co.kr/learn/courses/30/lessons/43164

코딩테스트 연습 - 여행경로

from copy import deepcopy

def solution(tickets):
    tickets.sort(key=lambda x:(x[0], x[1]))
    answer = []
    check = [0]*len(tickets)
    flag = 0
    def dfs(level, airport, path):
        nonlocal tickets, answer, flag
        if level == len(tickets):
            flag = 1
            answer = deepcopy(path)
            return
        if flag:
            return
        for idx in range(len(tickets)):
            if check[idx] == 0:
                if tickets[idx][0] == airport:
                    check[idx] = 1
                    path.append(tickets[idx][1])
                    dfs(level+1, tickets[idx][1], path)
                    check[idx] = 0
                    path.pop()

    dfs(0, "ICN", ["ICN"])
    return answer