HDOJ 1075 -- What Are You Talking About Trie( STL )

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方法一：Trie

思路：

1.   开辟一个结构体数组dict，数组中存放索引值和索引，比如from fiwo

2.   建立一颗Trie，Trie维护 整型变量 index，结构体指针数组 branch，在建立Trie的过程中，若是单词结尾，Trie中index赋值为dict的索引，否则为-1

 

写法一：string类降低编码复杂度，当然代价是时间复杂度加大约 2 倍

View Code

  1 /*

  2 PROG:   What Are You Talking About

  3 ID  :   yewei

  4 LANG:   C++

  5 */

  6 #include <map>

  7 #include <string>

  8 #include <cstdio>

  9 #include <cstdlib>

 10 #include <cstring>

 11 #include <iostream>

 12 #include <memory.h>

 13 #include <algorithm>

 14 using namespace std;

 15 

 16 struct Dictionary

 17 {

 18     string front, back;

 19 }dict[500004];

 20 

 21 struct Trie_Node

 22 {

 23     int index;

 24     Trie_Node *branch[27];

 25     Trie_Node(): index( -1 )

 26     {

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

 28     }

 29 };

 30 class Trie

 31 {

 32     public:

 33         Trie();

 34         ~Trie() { }

 35         void Trie_Insert( int k, string ss );

 36         int Trie_Find( string ss );

 37         

 38     private:

 39         Trie_Node *root;

 40 }t;

 41 

 42 /* Valiable */

 43 int M=0;

 44 

 45 Trie::Trie()

 46 {

 47     root = new Trie_Node();

 48 }// Trie

 49 

 50 void Trie::Trie_Insert( int k, string ss )

 51 {

 52     Trie_Node *ptr = root;

 53     int slen = ss.length();

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

 55     {

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

 57         {

 58             Trie_Node *temp = new Trie_Node();

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

 60         }

 61     

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

 63     }

 64     

 65     ptr->index = k;

 66 }// Trie_Insert

 67 

 68 int Trie::Trie_Find( string ss )

 69 {

 70     Trie_Node *ptr = root;

 71     int slen = ss.length();

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

 73     {

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

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

 76         else

 77             return -1;

 78     }

 79     

 80     return ptr->index;

 81 }// Trie_Find

 82 

 83 void ReadData()

 84 {

 85     string s1, s2;

 86     

 87     cin >> s1;   // Words " START "

 88     while ( cin >> s1 && s1!="END" )

 89     {

 90         cin >> s2;

 91         dict[M].front = s1;

 92         dict[M].back = s2;

 93         

 94         t.Trie_Insert( M++, s2 );   // Note " M++ "

 95     }// dictionary

 96 }// ReadData

 97 

 98 void Solve()

 99 {

100     int  slen, kk;

101     string words, line;

102     

103     cin >> line;  // Words " START "

104     getchar();

105     while ( getline( cin, line ) && line!="END" )

106     {

107         words = "";

108         slen = line.length();

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

110         {

111             if ( isalpha( line[i] ) )

112             {

113                 words += line[i];

114             }

115             else

116             {

117                 kk = t.Trie_Find( words );

118                 if ( kk==-1 )

119                     cout << words;

120                 else

121                     cout << dict[kk].front;

122                 cout << line[i];

123                 

124                 words = "";

125             }

126         }// scanning

127         

128         cout << endl;

129     }// books

130 }// Solve

131 

132 int main()

133 {

134     ReadData();

135     Solve();

136     

137     return 0;

138 }

写法二：C语言的写法，编码复杂度加大，时间复杂度尚可，250MS

View Code

  1 /*

  2 PROG:   What Are You Talking About

  3 ID  :   ouyangyewei

  4 LANG:   C++

  5 */

  6 #include <map>

  7 #include <string>

  8 #include <cstdio>

  9 #include <cstdlib>

 10 #include <cstring>

 11 #include <iostream>

 12 #include <memory.h>

 13 #include <algorithm>

 14 using namespace std;

 15 

 16 const int maxn = 15;

 17 

 18 struct Dictionary

 19 {

 20     char front[maxn];

 21     char back[maxn];

 22 }dict[500004]; 

 23 

 24 struct Trie_Node

 25 {

 26     int index;

 27     Trie_Node *branch[27];

 28     Trie_Node(): index( -1 )

 29     {

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

 31     }

 32 };

 33 class Trie

 34 {

 35     public:

 36         Trie();

 37         ~Trie() { }

 38         void Trie_Insert( int k, char ss[] );

 39         int Trie_Find( char ss[] );

 40         

 41     private:

 42         Trie_Node *root;

 43 }t;

 44 

 45 /* Valiable */

 46 int M=0;

 47 

 48 Trie::Trie()

 49 {

 50     root = new Trie_Node();

 51 }// Trie

 52 

 53 void Trie::Trie_Insert( int k, char ss[] )

 54 {

 55     Trie_Node *ptr = root;

 56     int slen = strlen( ss );

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

 58     {

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

 60         {

 61             Trie_Node *temp = new Trie_Node();

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

 63         }

 64     

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

 66     }

 67     

 68     ptr->index = k;

 69 }// Trie_Insert

 70 

 71 int Trie::Trie_Find( char ss[] )

 72 {

 73     Trie_Node *ptr = root;

 74     int slen = strlen( ss );

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

 76     {

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

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

 79         else

 80             return -1;

 81     }

 82     

 83     return ptr->index;

 84 }// Trie_Find

 85 

 86 void ReadData()

 87 {

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

 89     

 90     scanf("%s", &s1);   // Words " START "

 91     while ( EOF!=scanf("%s", s1), strcmp(s1, "END")!=0 )

 92     {

 93         scanf("%s", &s2);

 94         strcpy( dict[M].front, s1 );

 95         strcpy( dict[M].back, s2 );

 96         

 97         t.Trie_Insert( M++, s2 );   // Note " M++ "

 98     }// dictionary

 99 }// ReadData

100 

101 void Solve()

102 {

103     int  slen, tlen, kk;

104     char words[maxn], line[3004];

105     

106     scanf("%s", line);  // Words " START "

107     getchar();

108     while ( gets( line ), strcmp( line, "END" )!=0 )

109     {

110         tlen = 0;

111         slen = strlen( line );

112         memset( words, 0, sizeof(words) );

113         

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

115         {

116             if ( isalpha( line[i] ) )

117             {

118                 words[ tlen++ ] = line[i];

119             }

120             else

121             {

122                 kk = t.Trie_Find( words );

123                 if ( kk==-1 )

124                     printf("%s", words);

125                 else

126                     printf("%s", dict[kk].front);

127                 printf("%c", line[i]);

128                 

129                 tlen = 0;

130                 memset( words, 0, sizeof(words) );

131             }

132         }// scanning

133         

134         printf("\n");

135     }// books

136 }// Solve

137 

138 int main()

139 {

140     ReadData();

141     Solve();

142     

143     return 0;

144 }

 

方法二：STL  MAP

编码复杂度低，时间复杂度差

View Code

 1 /*

 2 PROG:   What Are You Talking About

 3 ID  :   ouyangyewei

 4 LANG:   C++

 5 */

 6 #include <map>

 7 #include <string>

 8 #include <cstdio>

 9 #include <cstdlib>

10 #include <cstring>

11 #include <iostream>

12 #include <memory.h>

13 #include <algorithm>

14 using namespace std;

15 

16 int slen;

17 string s1, s2, line, result;

18 map <string, string> data;

19 

20 int main()

21 {    

22     cin >> s1;   // START

23     while ( cin >> s1, s1!="END" )

24     {

25         cin >> s2;

26         data[ s2 ] = s1;

27     }// dictionary

28     

29     cin >> s1;

30     getchar();  // fetch carry reture

31     while ( getline( cin, line ) && line!="END" )

32     {

33         result = "";

34         slen = line.length();

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

36         {

37             if ( isalpha( line[i] ) )

38             {

39                 result += line[i];

40             }

41             else

42             {

43                 if ( data[ result ]=="" )

44                     cout << result;

45                 else

46                     cout << data[ result ];

47                 cout << line[i];

48                 

49                 result = "";

50             }

51         }// scanning

52         

53         cout << endl;

54     }// books

55     

56     return 0;

57 }