백준 1260. DFS와 BFS

https://www.acmicpc.net/problem/1260

import sys
from collections import deque
input = sys.stdin.readline

n, m, v = map(int,input().split())

link = [[] for _ in range(n+1)]

for _ in range(m):
    a, b = map(int,input().split())
    link[a].append(b)
    link[b].append(a)
    link[a].sort()
    link[b].sort()

dfs_visited = [0] * (n+1)
dfs_lst = []
def dfs(start):
    dfs_visited[start] = 1
    dfs_lst.append(start)
    for nxt in link[start]:
        if not dfs_visited[nxt]:
            dfs(nxt)

bfs_lst = [v]
bfs_visited = [0] * (n+1)
def bfs(start):
    q = deque([start])
    bfs_visited[start] = 1
    while q:
        now = q.popleft()
        for nxt in link[now]:
            if not bfs_visited[nxt]:
                q.append(nxt)
                bfs_visited[nxt] = 1
                bfs_lst.append(nxt)

dfs(v)
bfs(v)
print(*dfs_lst)
print(*bfs_lst)