백준 11725- 트리의 부모 찾기

 

 bfs로 풀어주었다.

 

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

N = int(input())
G = [[] for i in range(N+1)]

for _ in range(N-1):
    a, b = map(int, input().split())
    G[a].append(b)
    G[b].append(a)

q=deque()
q.append(1)
ancestor = {}
checked = [0] * (N+1)

while q:
    parent = q.popleft()
    for i in G[parent]:
        if not checked[i]:
            ancestor[i] = parent
            q.append(i)
            checked[i] = 1

for i in range(2,N+1):
    print(ancestor[i])