HDOJ 1247 -- Hat Words Trie

原创

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思路：先将所有的单词插入到 Trie 中，然后对于每个单词枚举前后位置

  1 /*

  2 PROG:   Hat’s Words

  3 ID  :   yewei

  4 LANG:   C++

  5 */

  6 #include <cstdio>

  7 #include <cstdlib>

  8 #include <cstring>

  9 #include <memory.h>

 10 

 11 //const int size = 102;

 12 const int maxn = 50004;

 13 

 14 struct Trie_Node

 15 {

 16     bool IsEnd;

 17     Trie_Node *branch[27];

 18     Trie_Node():IsEnd( false )

 19     {

 20         memset( branch, 0, sizeof(branch) );

 21     }// Init

 22 };

 23 

 24 class Trie

 25 {

 26     public:

 27         Trie();

 28         void Trie_Insert( char ss[] );

 29         bool Trie_Find( char ss[] );

 30     

 31     private:

 32         Trie_Node *root;

 33 }t;

 34 

 35 Trie::Trie()

 36 {

 37     root = new Trie_Node();

 38 }// Trie

 39 

 40 void Trie::Trie_Insert( char ss[] )

 41 {

 42     Trie_Node *ptr = root;

 43     int slen = strlen( ss );

 44     for ( int i=0; i<slen; ++i )

 45     {

 46         if ( ptr->branch[ ss[i]-'a' ]==NULL )

 47         {

 48             Trie_Node *temp = new Trie_Node();

 49             ptr->branch[ ss[i]-'a' ] = temp;

 50         }

 51         

 52         ptr = ptr->branch[ ss[i]-'a' ];

 53     }// End of for

 54     

 55     ptr->IsEnd = true;

 56     //delete temp;

 57 }// Trie_Insert

 58 

 59 bool Trie::Trie_Find( char ss[] )

 60 {

 61     Trie_Node *ptr = root;

 62     int slen = strlen( ss );

 63     for ( int i=0; i<slen; ++i )

 64     {

 65         if ( ptr->branch[ ss[i]-'a' ]!=NULL )

 66             ptr = ptr->branch[ ss[i]-'a' ];

 67         else

 68             return false;

 69     }

 70     

 71     return ptr->IsEnd;

 72 }// Trie_Find

 73 

 74 int  M=0;

 75 char words[maxn][15];

 76 

 77 void ReadData()

 78 {

 79     while ( EOF!=scanf("%s", words[M]) )

 80     {

 81         t.Trie_Insert( words[M++] );

 82     }// Insert into Trie

 83 }// ReadData

 84 

 85 void Solve()

 86 {

 87     int  tlen;

 88     char s1[15], s2[15];

 89     for ( int i=0; i<M; ++i )

 90     {

 91         tlen = strlen( words[i] );

 92         if ( tlen<2 )   continue;

 93         for ( int j=1; j<tlen; ++j )

 94         {

 95             memset( s1, 0, sizeof(s1) );

 96             memset( s2, 0, sizeof(s2) );

 97             strncpy( s1, words[i], j );

 98             strcpy( s2, words[i]+j );

 99             

100             if ( t.Trie_Find( s1 ) && t.Trie_Find( s2 ) )

101             {

102                 printf("%s\n", words[i]);

103                 break;

104             }    

105         }

106     }// End of for

107 }// Solve

108 

109 int main()

110 {

111     ReadData();

112     Solve();

113     

114     return 0;

115 }