Skip to content

1138 Postorder Traversal

Statement

Metadata

  • 作者: CHEN, Yue
  • 单位: 浙江大学
  • 代码长度限制: 16 KB
  • 时间限制: 650 ms
  • 内存限制: 64 MB

Suppose that all the keys in a binary tree are distinct positive integers. Given the preorder and inorder traversal sequences, you are supposed to output the first number of the postorder traversal sequence of the corresponding binary tree.

Input Specification

Each input file contains one test case. For each case, the first line gives a positive integer N (\le 50,000), the total number of nodes in the binary tree. The second line gives the preorder sequence and the third line gives the inorder sequence. All the numbers in a line are separated by a space.

Output Specification

For each test case, print in one line the first number of the postorder traversal sequence of the corresponding binary tree.

Sample Input 

7
1 2 3 4 5 6 7
2 3 1 5 4 7 6

Sample Output 

3

Last update: May 4, 2022
Back to top