1991.md

1991

Python

내 풀이

N = int(input())

tree = {}
for _ in range(N):
    key, left, right = input().split()
    tree[key] = (left, right)

def preorder(key, tree):
    print(key ,end='')
    if tree[key][0] != '.':
        preorder(tree[key][0], tree)
    if tree[key][1] != '.':
        preorder(tree[key][1], tree)


def inorder(key, tree):
    if tree[key][0] != '.':
        inorder(tree[key][0], tree)
    print(key ,end='')
    if tree[key][1] != '.':
        inorder(tree[key][1], tree)

def postorder(key, tree):
    if tree[key][0] != '.':
        postorder(tree[key][0], tree)
    if tree[key][1] != '.':
        postorder(tree[key][1], tree)
    print(key ,end='')

preorder('A', tree)
print()
inorder('A', tree)
print()
postorder('A', tree)

클래스 버전

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


def preorder(node):  # 전위 순회
    print(node.item, end='')
    if node.left != '.':
        preorder(tree[node.left])
    if node.right != '.':
        preorder(tree[node.right])


def inorder(node):  # 중위 순회
    if node.left != '.':
        inorder(tree[node.left])
    print(node.item, end='')
    if node.right != '.':
        inorder(tree[node.right])


def postorder(node):  # 후위 순회
    if node.left != '.':
        postorder(tree[node.left])
    if node.right != '.':
        postorder(tree[node.right])
    print(node.item, end='')


if __name__ == "__main__":

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

    for _ in range(N):
        node, left, right = map(str, input().split())
        tree[node] = Node(node, left, right)

    # print(tree)

    preorder(tree['A'])
    print()
    inorder(tree['A'])
    print()
    postorder(tree['A'])