Trie树的参考代码

Trie树的参考代码 （zz）

2008-05-27 18:11

这个例子是用来搜索查找字的词性，假设刚开始建好了字库。 类中的remove函数还没实现，具体的可以先遍历到单词在trie树的最低层结点，从下往上删除结点，碰到某个结点有2或2个以上子结点时停止。 为了降低空间代价，可以用一个大数组来储存字库。而在结点中只需存储该单词在数组中的位置即可。对于非叶结点，用-1表示。 在具体编程过程中，可参照程序代码适当修改以适应具体要求。 #include #include #include using namespace std; const int num_chars = 26; class Trie { public:        Trie();        Trie(Trie& tr);      virtual ~Trie();      int trie_search(const char* word, char* entry ) const;      int insert(const char* word, const char* entry); // int remove(const char* word, char* entry); protected:      struct Trie_node      {          char* data;            Trie_node* branch[num_chars];            Trie_node();      };             Trie_node* root; }; Trie::Trie_node::Trie_node() {       data = NULL;     for (int i=0; i          branch[i] = NULL; } Trie::Trie():root(NULL) { } Trie::~Trie() { } int Trie::trie_search(const char* word, char* entry ) const {     int position = 0;     char char_code;       Trie_node *location = root;     while( location!=NULL && *word!=0 )     {         if (*word>='A' && *word<='Z')               char_code = *word-'A';         else if (*word>='a' && *word<='z')               char_code = *word-'a';         else return 0;           location = location->branch[char_code];           position++;           word++;     }     if ( location != NULL && location->data != NULL )     {         strcpy(entry,location->data);         return 1;     }     else return 0; } int Trie::insert(const char* word, const char* entry) {     int result = 1, position = 0;     if ( root == NULL ) root = new Trie_node;     char char_code;       Trie_node *location = root;     while( location!=NULL && *word!=0 )     {         if (*word>='A' && *word<='Z')               char_code = *word-'A';         else if (*word>='a' && *word<='z')               char_code = *word-'a';         else return 0;         if( location->branch[char_code] == NULL )               location->branch[char_code] = new Trie_node;           location = location->branch[char_code];           position++;           word++;     }     if (location->data != NULL)           result = 0;     else {           location->data = new char[strlen(entry)+1];         strcpy(location->data, entry);     }     return result; } int main() {       Trie t; char entry[100];       t.insert("aa", "DET");       t.insert("abacus","NOUN");       t.insert("abalone","NOUN");       t.insert("abandon","VERB");       t.insert("abandoned","ADJ");       t.insert("abashed","ADJ");       t.insert("abate","VERB");       t.insert("this", "PRON");     if (t.trie_search("this", entry))         cout<<"'this' was found. pos: "<    if (t.trie_search("abate", entry))         cout<<"'abate' is found. pos: "<    if (t.trie_search("baby", entry))         cout<<"'baby' is found. pos: "<    else         cout<<"'baby' does not exist at all!"<        if (t.trie_search("aa", entry))         cout<<"'aa was found. pos: "<return 0; }