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");
}
}