http://acm.hdu.edu.cn/showproblem.php?pid=1247

Hat’s Words

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 7760    Accepted Submission(s): 2814


Problem Description
A hat’s word is a word in the dictionary that is the concatenation of exactly two other words in the dictionary.
You are to find all the hat’s words in a dictionary.
 

 

Input
Standard input consists of a number of lowercase words, one per line, in alphabetical order. There will be no more than 50,000 words.
Only one case.
 

 

Output
Your output should contain all the hat’s words, one per line, in alphabetical order.
 

 

Sample Input
a
ahat
hat
hatword
hziee
word
 

 

Sample Output
ahat
hatword
 

////////////////////////////////////////////////////////////////////////////////////////////////////

可以用map做，但是用字典树好一点，暂时还不会，留个坑

#include <stdio.h>
#include <string.h>
#include <map>
#include <iostream>
#include <algorithm>

using namespace std;

int main()
{
    string str[50010];
    int tmp=0;
    int tot=0;
    map<string,int> cas;
    while(cin>>str[tot++])
    {
         cas[str[tot-1]]=1;
    }
    for(int i=0;i<tot;i++)
    {
        for(int j=1;j<str[i].length();j++)
        {
              if(cas[str[i].substr(0,j)]==1 && cas[str[i].substr(j)]==1)
              {
                  cout<<str[i]<<endl;
                  break;
              }
        }
    }
    return 0;
}