파이썬으로 풀어보는 백준 1991번: 트리 순회

https://www.acmicpc.net/problem/1991

1991번: 트리 순회

 

 

내 풀이:

class Node:
    def __init__(self, data):
        self.data = data
        self.left = None
        self.right = None
 
 
class Tree:
    def __init__(self, root, left, right):
        self.root = Node(root)
        if left != '.':
            self.root.left = Node(left)
        if right != '.':
            self.root.right = Node(right)
        self.current = self.root
 
 
    def append(self, parent, left, right):
        self.current = self.root
        stack = []
        if self.current.right:
            stack.append(self.current.right)
        if self.current.left:
            stack.append(self.current.left)
        while stack:
            self.current = stack.pop()
            if self.current.data == parent:
                if left != '.':
                    self.current.left = Node(left)
                if right != '.':
                    self.current.right = Node(right)
                return
 
            if self.current.right:
                stack.append(self.current.right)
            if self.current.left:
                stack.append(self.current.left)
 
 
    def PreOrder(self, now):
        print(now.data, end='')
        if now.left:
            self.PreOrder(now.left)
        if now.right:
            self.PreOrder(now.right)
 
    def InOrder(self, now):
        if now.left:
            self.InOrder(now.left)
        print(now.data, end='')
        if now.right:
            self.InOrder(now.right)
 
    def PostOrder(self, now):
        if now.left:
            self.PostOrder(now.left)
        if now.right:
            self.PostOrder(now.right)
        print(now.data, end='')
 
 
N = int(input())
root, left, right = input().split()
tree = Tree(root, left, right)
for _ in range(N-1):
    parent, left, right = input().split()
    tree.append(parent, left, right)
 
tree.PreOrder(tree.root)
print()
tree.InOrder(tree.root)
print()
tree.PostOrder(tree.root)
print()

Python3, 64ms

클래스를 이용한 트리의 구현.