문제 링크
https://www.acmicpc.net/problem/1991
풀이 방식
전체 코드
from sys import stdin
def pre_order(root):
if root != '.':
print(root, end='')
pre_order(tree[root][0])
pre_order(tree[root][1])
def in_order(root):
if root != '.':
in_order(tree[root][0])
print(root, end='')
in_order(tree[root][1])
def post_order(root):
if root != '.':
post_order(tree[root][0])
post_order(tree[root][1])
print(root, end='')
N = int(input())
tree = {}
for i in range(N):
node, left, right = stdin.readline().split()
tree[node] = [left, right]
pre_order('A')
print()
in_order('A')
print()
post_order('A')