노트

n = int(input()) tree = {} for _ in range(n): root, left, right = input().split() tree[root] = [left,right] def preorder(a): if a is not '.': print(a,end='') preorder(tree[a][0]) preorder(tree[a][1]) def inorder(a): if a is not '.': inorder(tree[a][0]) print(a,end='') inorder(tree[a][1]) def postorder(a): if a is not '.': postorder(tree[a][0]) postorder(tree[a][1]) print(a,end='') preorder('A') ..