Suppose that all the keys in a binary tree are distinct positive integers. Given the postorder and inorder traversal sequences, you are supposed to output the level order 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 (<=30), the total number of nodes in the binary tree. The second line gives the postorder 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 level order traversal sequence of the corresponding binary tree. All the numbers in a line must be separated by exactly one space, and there must be no extra space at the end of the line.

Sample Input:

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

Sample Output:

4 1 6 3 5 7 2

#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <vector>
#include <queue>
using namespace std;const int maxn=40;
int post[maxn];
int in[maxn];struct node
{int data;node *lchild,*rchild;
};node * creat(int postL,int postR,int inL,int inR)
{if(postL>postR) return NULL;node * root=new node;root->data=post[postR];int index;for(index=inL;index<=inR;index++){if(in[index]==post[postR]){break;}}int numLeft=index-inL;root->lchild=creat(postL,postL+numLeft-1,inL,index-1);root->rchild=creat(postL+numLeft,postR-1,index+1,inR);return root;
}int first_flag=0;void layerOrder(node * root)
{queue<node *> ans;ans.push(root);while(!ans.empty()){node * tmp=ans.front();ans.pop();if(first_flag!=0){cout<<" ";}cout<<tmp->data;first_flag=1;if(tmp->lchild!=NULL) ans.push(tmp->lchild);if(tmp->rchild!=NULL) ans.push(tmp->rchild);}
}int main()
{int n;cin>>n;for(int i=0;i<n;i++){cin>>post[i];}for(int i=0;i<n;i++){cin>>in[i];}node * root;root=creat(0,n-1,0,n-1);layerOrder(root);return 0;
}