PROGRAMMING:Creating binary tree with preorder sequence
Write a program, read in a string of user input sequence traversal string, according to this string to establish a binary tree (binary list storage). For example, the following traversal string: ABC ######################################35. Then the binary tree is traversed in middle order, and the traversal results are output.
###Input format:
Multiple groups of test data, each test data line, the line has only one string, the length is not more than 100.
###Output format:
For each group of data,
Binary tree output in order to traverse the sequence, each character is followed by a space.
Each group outputs one line, corresponding to one line of input string.
###Input example: (and its corresponding binary tree)
```in
abc##de#g##f###
```
###Output example:
```out
c b e g d f a
```
answer：If there is no answer, please comment
###Input format:
Multiple groups of test data, each test data line, the line has only one string, the length is not more than 100.
###Output format:
For each group of data,
Binary tree output in order to traverse the sequence, each character is followed by a space.
Each group outputs one line, corresponding to one line of input string.
###Input example: (and its corresponding binary tree)
```in
abc##de#g##f###
```
###Output example:
```out
c b e g d f a
```
answer：If there is no answer, please comment