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21730_RECONSTRUCTINGTREES

2022-5-16 18:20| 发布者: Hocassian| 查看: 27| 评论: 0|原作者: 肇庆学院ACM合集

摘要:

C:\Users\Administrator\Downloads\2019-10-12-10-14-4-89505797764600-Problem List-采集的数据-后羿采集器.html

Pro.ID

21730

Title

RECONSTRUCTING TREES

Title链接

http://10.20.2.8/oj/exercise/problem?problem_id=21730

AC

Submit

Ratio

时间&空间限制

Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 131072/65536 K (Java/Others)

描述

It is very easy to produce the various traversals of a binary tree, however this problem requires you to produce the tree from the traversals. Specifically, given the pre-order and in-order traversals of a binary tree (not necessarily a binary search tree), reconstruct, if possible, the original tree.

For instance, the following tree will produce the traversals shown

/ \

D F

/ \

B G

/ \ \

A C I

/ \

H K

Preorder : EDBACFGIHKJ

Inorder : ABCDEFGHIJK

Postorder: ACBDHJKIGFE

输入

Input will consist of representations of several trees, each on a single line, and terminated by a #. Each line will consist of two strings of up to 26 unique uppercase letters in the form

<pre-order> <space> <in-order>.

You can assume that the two strings will be permutations of each other.

输出

Description

For instance, the following tree will produce the traversals shown

/ \

D F

/ \

B G

/ \ \

A C I

/ \

H K

Preorder : EDBACFGIHKJ

Inorder : ABCDEFGHIJK

Postorder: ACBDHJKIGFE

Input

Input will consist of representations of several trees, each on a single line, and terminated by a #. Each line will consist of two strings of up to 26 unique uppercase letters in the form

<pre-order> <space> <in-order>.

You can assume that the two strings will be permutations of each other.

Output

Output will consist of the post-order traversal of the reconstructed tree if possible, otherwise the words 'Invalid tree'.

Sample Input

EDBACFGIHKJ ABCDEFGHIJK

Sample Output

ACBDHJKIGFE

Source

New Zealand PC 2008