题解 | #二叉树遍历#

import sys
def creat(node,string,index):
    if(index==len(string)):
        return -1
    if(index>-1):
        char=string[index]
        if(char !='#'):
            node.val=char
            index+=1
            if(index<len(string)):
                if(string[index]!='#'):
                    node.left=TreeNode()
                    index = creat(node.left,string,index)
                else: index+=1
            if(index>-1 and index<len(string)):
                if(string[index]!='#'):
                    node.right=TreeNode()
                    index = creat(node.right,string,index)
                else: index+=1
        else: index+=1
    return index

def inorder(node):
    if(node!=None):
        inorder(node.left)
        print(node.val,end=' ')
        inorder(node.right)
class TreeNode(object):
    def __init__(self, val=''):
        self.val = val
        self.left = None
        self.right = None


for line in sys.stdin:
    string = list(line)
    #print(string)
    Tree = TreeNode() #实例化
    creat(Tree,string,0)
    #print(Tree)
    inorder(Tree)