Backjun-グラフ(#1991)

Code

import sys

def pre_traversal(node):
    print(node,end='')
    left_node, right_node = tree[node]
    if left_node != '.':
        pre_traversal(left_node)
    if right_node != '.':
        pre_traversal(right_node)

def in_traversal(node):
    left_node, right_node = tree[node]
    if left_node != '.':
        in_traversal(left_node)
    print(node,end='')
    if right_node != '.':
        in_traversal(right_node)


def post_traversal(node):
    left_node, right_node = tree[node]
    if left_node != '.':
        post_traversal(left_node)
    if right_node != '.':
        post_traversal(right_node)
    print(node,end='')
            


n = int(input())
tree = {}
for _ in range(n):
    comp = sys.stdin.readline().split()
    tree.setdefault(comp[0],comp[1:])
    
pre_traversal('A')
print('')
in_traversal('A')
print('')
post_traversal('A')