# 树的遍历转换

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

const int maxn = 1000;

typedef struct BTNode{
char data;
struct BTNode *lchild;
struct BTNode *rchild;
}BTNode, *BinTree;

BinTree create(char *pre, char *in, int len){
BinTree T;
int i;
if(len == 0)  return NULL;
T = (BTNode *)malloc(sizeof(BTNode));
T -> data = pre[0]; //当前节点数据为先序遍历第一个元素
for(i = 0; i < len; i ++){  //中序遍历中找根节点
if(pre[0] == in[i]) break;
}
//左子树的先序遍历起始点即为当前先序遍历的下一位置，中序遍历起始位置不变，长度为中序遍历根节点左侧部分
T -> lchild = create(pre + 1, in, i);
T -> rchild = create(pre + i + 1, in + i + 1, len - i - 1);
//右子树先序遍历起始点为当前先序遍历左子树之后部分，中序同，长度为当前长度减左子树减1（当前节点）
return T;
}

int height(BinTree T){
int h, l, r;
if(T == NULL) h = 0;
else{
l = height(T -> lchild);
r = height(T -> rchild);
h = max(l, r) + 1;
}
return h;
}

int main(){
int n;
char pre[55], in[55];
BinTree T = NULL;
scanf("%d", &n);
scanf("%s\n%s", pre, in);
T = create(pre, in, n);
printf("%d\n", height(T));
return 0;
}



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

const int maxn = 1000;

typedef struct BTNode{
int data;
struct BTNode *lchild;
struct BTNode *rchild;
}BTNode, *BinTree;

BinTree create(int post[], int in[], int len){
BinTree T;
int i;
if(len == 0)  return NULL;
T = (BTNode *)malloc(sizeof(BTNode));
T -> data = post[len - 1]; //当前节点数据为后序遍历最后一个节点
for(i = 0; i < len; i ++){  //中序遍历中找根节点
if(post[len - 1] == in[i]) break;
}
T -> lchild = create(post, in, i);
T -> rchild = create(post + i, in + i + 1, len - i - 1);
return T;
}

int cnt = 0;
int n;

void print(BinTree T){
queue<BinTree> q;
q.push(T);

while(!q.empty()){
BinTree now = q.front();
q.pop();
cnt ++;
printf("%d", now->data);
if(cnt != n)    printf(" ");
if(now->lchild != NULL) q.push(now->lchild);
if(now->rchild != NULL) q.push(now->rchild);
}
}

int main(){

int post[55], in[55];
BinTree T = NULL;
scanf("%d", &n);
for(int i = 0; i < n; i ++)   scanf("%d", &post[i]);
for(int i = 0; i < n; i ++)   scanf("%d", &in[i]);
T = create(post, in, n);
print(T);
return 0;
}