zoukankan      html  css  js  c++  java
  • 1138 Postorder Traversal (25 分)

    Suppose that all the keys in a binary tree are distinct positive integers. Given the preorder and inorder traversal sequences, you are supposed to output the first number of the postorder 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 (≤ 50,000), the total number of nodes in the binary tree. The second line gives the preorder 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 first number of the postorder traversal sequence of the corresponding binary tree.

    Sample Input:

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

    Sample Output:

    3
     
    #include<bits/stdc++.h>
    using namespace std;
    vector<int> pre,post,in;
    void toPost(int root,int inL,int inR){
        if(inL>inR){
            return ;
        }
        int k;
         for(k=inL;k<=inR;k++){
                if(in[k]==pre[root]){
                    break;
                }
         }
        int len=k-inL;
        toPost(root+1,inL,k-1);
        toPost(root+len+1,k+1,inR);
        post.push_back(pre[root]);
    }
    int main(){
        int n;
        cin>>n;
        pre.resize(n);
        in.resize(n);
        for(int i=0;i<n;i++){
            cin>>pre[i];
        }
        for(int i=0;i<n;i++){
            cin>>in[i];
        }
        toPost(0,0,n-1);
        cout<<post[0]<<endl;
        
        return 0;
    }
     
  • 相关阅读:
    团队项目前期冲刺-6
    《人月神话》阅读笔记02
    4.25软件工程课下作业
    团队项目前期冲刺-5
    element-UI table封装
    local storage
    去除2个数组中不同的数字
    vue.config.js常用配置
    工作中使用的一些技巧总结【后续持续性更新】
    MockJs
  • 原文地址:https://www.cnblogs.com/dreamzj/p/14444180.html
Copyright © 2011-2022 走看看