zoukankan      html  css  js  c++  java
  • Tree

    Tree

    描述

    Little Valentine liked playing with binary trees very much. Her favorite game was constructing randomly looking binary trees with capital letters in the nodes.  This is an example of one of her creations: 

                                                    D
    
                                                  / 
    
                                                 /   
    
                                                B     E
    
                                               /      
    
                                              /        
    
                                             A     C     G
    
                                                        /
    
                                                       /
    
                                                      F

    To record her trees for future generations, she wrote down two strings for each tree: a preorder traversal (root, left subtree, right subtree) and an inorder traversal (left subtree, root, right subtree). For the tree drawn above the preorder traversal is DBACEGF and the inorder traversal is ABCDEFG.  She thought that such a pair of strings would give enough information to reconstruct the tree later (but she never tried it). 
    Now, years later, looking again at the strings, she realized that reconstructing the trees was indeed possible, but only because she never had used the same letter twice in the same tree.  However, doing the reconstruction by hand, soon turned out to be tedious.  So now she asks you to write a program that does the job for her! 

     
    输入
    The input will contain one or more test cases.  Each test case consists of one line containing two strings preord and inord, representing the preorder traversal and inorder traversal of a binary tree. Both strings consist of unique capital letters. (Thus they are not longer than 26 characters.)  Input is terminated by end of file.
    输出
    For each test case, recover Valentine's binary tree and print one line containing the tree's postorder traversal (left subtree, right subtree, root).
    样例输入
    DBACEGF ABCDEFG
    BCAD CBAD
    样例输出
    ACBFGED
    CDAB

     
    #include <iostream>
    #include <string>
    
    using namespace std;
    string pos;
    void convert(string pre,string in)
    {
        
        
        if(in.size()==1)
            pos+=in;
        else
        {
            int k=in.find(pre.substr(0,1));
    
            if(k>0)
                convert(pre.substr(1,k),in.substr(0,k));
            if(k<in.size()-1)
                convert(pre.substr(k+1,pre.size()-k-1),in.substr(k+1,in.size()-k-1));
    
            pos+=in[k];
        }
    
    
    }
    
    int main()
    {
        string str_pre;
        string str_in;
        
        while(cin>>str_pre>>str_in && !cin.eof())
        {
    
        convert(str_pre,str_in);
    
        cout<<pos<<endl;
        pos = "";
        
        }
    
        return 0;
    }        
  • 相关阅读:
    windows启动、停止和重新启动Apache服务
    Mysql用户密码设置修改和权限分配
    MySQL数据库恢复(使用mysqlbinlog命令)
    影响MySQL性能的五大配置参数
    PHP获取文件后缀名的三种方法
    php 设计模式
    蓦然回首,那人却在灯火阑珊处
    websocket消息推送实现
    Spring任务调度之Quartz
    使用easyui的form提交表单,在IE下出现类似附件下载时提示是否保存的现象
  • 原文地址:https://www.cnblogs.com/imwtr/p/4069533.html
Copyright © 2011-2022 走看看