字典树的数据结构及基本算法的实现

#include <iostream>



using namespace std;



const int branchNum = 26;//声明常量



struct Trie_node{

	bool isStr;//记录此处是否构成一个串。

	Trie_node* next[branchNum];//指向各个子树的指针,下标0-25代表26字符

	Trie_node():isStr(false){

		memset(next,NULL,sizeof(next));

	}

};





class Trie{

public:

	Trie();

	void insert(const char* word);

	bool search(char* word);

	void deleteTrie(Trie_node* root);



private:

	Trie_node* root;

};



Trie::Trie(){

	root = new Trie_node();

}



void Trie::insert(const char* word){

	Trie_node* location = root;

	while(*word){

		if(location->next[*word - 'a'] == NULL){//不存在则建立

			Trie_node* tmp = new Trie_node();

			location->next[*word - 'a'] = tmp;

		}



		location = location->next[*word - 'a']; //每插入一步，相当于有一个新串经过，指针要向下移

		++word;

	}

	location->isStr = true;//到达尾部,标记一个串

}



bool Trie::search(char* word){

	Trie_node* location = root;

	while(*word && location){

		location = location->next[*word - 'a'];

		++word;

	}



	return (location!=NULL && location->isStr);

}





void Trie::deleteTrie(Trie_node* root){

	int i;

	for(i = 0 ; i < branchNum ; ++i){

		if(root->next[i] != NULL){

			deleteTrie(root->next[i]);

		}

	}



	delete root;

}





int main(){

	Trie t;

	t.insert("a");

	t.insert("abandon");

	char* c = "abandoned";

	t.insert(c);

	t.insert("abashed");

	if(t.search("abashed")){

		printf("true\n");

	}

}