二叉树二叉树，学学建树

题目
根据后序，中序建树，得出层序遍历，嗯很不错

#include <bits/stdc++.h>
using namespace std;

const int MAXN = 35;
const int INF = 0x3f3f3f3f;

int n, maxlevel;//最大深度 
int in[MAXN], post[MAXN];	//存储中序遍历、后续遍历
deque<int> level[MAXN];		//存储层序遍历
//root n-1 
//left 0 
//right n-1 
//deep 1 
void travel(int root, int left, int right, int deep){
	//root 当前根节点 
    if(left > right)
        return ;
    
    int i = left;
    	//找到中序遍历中的根节点
    while(i <= right && in[i] != post[root])
        i++;

    maxlevel = max(deep, maxlevel);
    level[deep].push_back(post[root]);

    travel(root - right + i - 1, left, i - 1, deep + 1);	//遍历左子树
    travel(root - 1, i + 1, right, deep + 1);				//遍历右子树
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    cin >> n;
    for(int i = 0;i < n;i ++)//中序 
        cin >> in[i];
    
    for(int i = 0;i < n;i ++)//后序 
        cin >> post[i];
    

	maxlevel = 0;	//记录最大深度
    travel(n - 1, 0, n - 1, 1);

    cout << "R:";
    for(int i = 1;i <= maxlevel;i++){
        cout << " " << level[i].back();
    }
    cout << endl << "L:";
    for(int i = 1;i <= maxlevel;i++){
        cout << " " << level[i].front();
    }
    return 0;
}