[백준] 1991 : 트리 순회 python

 

이코테의 트리 순회 강좌를 보고 짠 코드

import sys
input = sys.stdin.readline

class Node:
    def __init__(self, data, left, right):
        self.data=data
        self.left=left
        self.right=right

def pre_order(node):
    print(node.data, end='')
    if node.left!=None:
        pre_order(tree[node.left])
    if node.right!=None:
        pre_order(tree[node.right])

def in_order(node):
    if node.left!=None:
        in_order(tree[node.left])
    print(node.data,end='')
    if node.right!=None:
        in_order(tree[node.right])

def post_order(node):
    if node.left!=None:
        post_order(tree[node.left])
    if node.right!=None:
        post_order(tree[node.right])
    print(node.data,end='')

n = int(input())
tree = {}

for i in range(n):
    data, left, right = input().split()
    if left=='.':
        left=None
    if right=='.':
        right=None
    tree[data] = Node(data,left,right)
pre_order(tree['A'])
print()
in_order(tree['A'])
print()
post_order(tree['A'])

 

 

클래스를 사용하지 않고 짠 코드

import sys
input = sys.stdin.readline

def pre_order(root):
    if root!=None:
        print(root,end='')
        pre_order(tree[root][0])
        pre_order(tree[root][1])

def in_order(root):
    if root!=None:
        in_order(tree[root][0])
        print(root,end='')
        in_order(tree[root][1])

def post_order(root):
    if root!=None:
        post_order(tree[root][0])
        post_order(tree[root][1])
        print(root,end='')

n = int(input())
tree = {}

for i in range(n):
    data, left, right = input().split()
    if left=='.':
        left=None
    if right=='.':
        right=None
    tree[data] = [left,right]

pre_order('A')
print()
in_order('A')
print()
post_order('A')