数据结构实验之二叉树四：（先序中序）还原二叉树

数据结构实验之二叉树四：（先序中序）还原二叉树
Time Limit: 1000MS Memory Limit: 65536KB
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Problem Description

给定一棵二叉树的先序遍历序列和中序遍历序列，要求计算该二叉树的高度。
Input

输入数据有多组，每组数据第一行输入1个正整数N(1 <= N <= 50)为树中结点总数，随后2行先后给出先序和中序遍历序列，均是长度为N的不包含重复英文字母(区分大小写)的字符串。

Output

输出一个整数，即该二叉树的高度。
Example Input

9
ABDFGHIEC
FDHGIBEAC
Example Output

5
Hint

Author

xam

#include <iostream>#include <cstdio>#include <cstring>using namespace std;const int MAX = 55;typedef struct node{    char data;    struct node *cl, *cr;} tree, *ptree;ptree get_pretree(int n, char pre[], char mid[]){    if (n == 0)        return NULL;    char *p;    for (p = mid; p != '\0'; p++)    {        if (*p == pre[0])            break;    }    int len = p - mid;    ptree root = new tree;    root->data = pre[0];    root->cl = get_pretree(len, pre + 1, mid);    root->cr = get_pretree(n - len - 1, pre + len + 1, p + 1);    return root;}int get_deep(ptree root){    if (root == NULL)        return 0;    int dp = 0;    int dl = get_deep(root->cl);    int dr = get_deep(root->cr);    dp = dl > dr ? dl + 1 : dr + 1;    return dp;}int main(){    char pre[MAX], mid[MAX];    int n;    while (cin >> n)    {        cin >> pre >> mid;        ptree root = NULL;        root = get_pretree(n, pre, mid);        int ct = get_deep(root);        cout << ct << endl;    }    return 0;}