Degree of Skewness

题目描述

Given a binary tree, let $nL$​ denotes the number of nodes with only a left child, and $nR​$ the number of nodes with only a right child. The degree of skewness is defined to be $Ds​=nL​−nR​$. Your job is to calculate $Ds​$ for a given binary tree.

输入格式

Each input file contains one test case. For each case, the first lines gives a positive integer $n (≤10^3)$ which is the number of nodes in the binary tree. The next two lines contain the post-order and in-order traversal sequences of the tree, respectively. The keys are integers from $1$ to $n$. All the numbers in a line are seperated by a space.

输出格式

Print in a line the degree of skewness in the format:

Ds​ = nL​ - nR​

样例 #1

样例输入 #1

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

样例输出 #1

2 = 3 - 1