Binary tree level traversal 2
【Question Description】
For a binary tree, its pre-order traversal is ABDEGCFHI, and its in-order traversal is DBGEACHFI, and the result of its hierarchical traversal is ABCDEFGHI.
It can be proved that, given the known preorder and inorder traversal, the result of a binary tree and its level traversal can be uniquely determined. According to the given pre-order and in-order traversal, output the result of the hierarchical traversal of this binary tree.
【Enter description】
The first line is a string representing the preorder traversal of the binary tree.
The second line is a string representing the in-order traversal of the binary tree.
The nodes of a binary tree are always represented by uppercase or lowercase letters, and the number of nodes is not more than 100.
[Output description]
Output the level traversal of the binary tree, one line of characters.
【Input sample】
ABDEGCFHI
DBGEACHFI
【Example of output】
ABCDEFGHI
how to do it