HDu--1247-HAt’s Words(一般)

Hat’s Words
Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 5772    Accepted Submission(s): 2154
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
   
   
   
   
   
   
   
   

    
    
    
     
   
   
   
   
   
   
   
   

    
    
    
     
   
   
   
   
   
   
   
   

    
    
    
     
   
   
   
   
   
   
   
   

    
    
    
     
   
   
   
   
   
   
   
   

    
    
    
    
#include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;
const int MAXN=26;
const int MAX=50005;
char word[MAX][27];

struct node
{
   bool is;
   node *next[MAXN];
   node()
   {
      is=false;
      memset(next,0,sizeof(next));
   }
};

void Insert(node *rt,char *s)
{
    int i=0;
    node *p=rt;
    while(s[i])
    {
         int k=s[i++]-'a';
         if(p->next[k]==NULL)
            p->next[k]=new node();
         p=p->next[k];
    }
    p->is=true; //        
 
}

bool Search(node *rt,char s[])
{
	int i=0,top=0,stack[1000];
	node *p=rt;
	while(s[i])
	{
		int k=s[i++]-'a';
		if(p->next[k]==NULL) return 0;
		p=p->next[k];
		if(p->is && s[i])//               
			stack[top++]=i;//  
	}
	while(top)//         
 
	{
	    bool ok=1;
		i=stack[--top];
		p=rt;
		while(s[i])
		{
			int k=s[i++]-'a';
			if(p->next[k]==NULL)
			{
				ok=false;
				break;
			}
			p=p->next[k];
		}
		if(ok && p->is)//    ，      
			return 1;
	}
	return 0;
}

int main()
{
    int i=0;
    node *rt=new node();
    while(gets(word[i]))
    {
        Insert(rt,word[i]);
        i++;
	}
	for(int j=0;j<i;j++)
		if(Search(rt,word[j]))
		   printf("%s
",word[j]);
    return 0;
}