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
");
	}
}