Implement Trie (Prefix Tree)

Implement a trie with insert , search , and startsWith methods.

Note:
You may assume this all inputs is consist of lowercase letters a-z .

Analyse:for each node, it has a children, from a-Z.

1. For the string insertion operation, the procedure is:

--set Root as the temp node;

--for every character in the string, compute it corresponding place at the branch, and mark them.

--after all characters is marked, set Isval to indicate it ' s a value rather than a prefix.

2. For the search operation, the procedure is:

--set Root as the temp node;

--for every character in the string, continuously check the existance of it. If NULL node encountered, jump out the of loop.

--if the node is empty and then return false; Else, we need to judge whether this string is a value or a prefix.

3. For the startwith operation, it's quite similiar to the search operation except this all search operations with true re Sult returned can return true in the start operation.

Runtime:64ms.

1 classTrienode {2  Public:3     //Initialize your data structure here.4trienode* childnode[ -];5     BOOLIsval;//To indicate whether the leaf node is the target word or the prefix6 Trienode () {7Isval =false;8          for(inti =0; I < -; i++)9Childnode[i] =NULL;Ten     } One }; A  - classTrie { -  Public: the Trie () { -Root =NewTrienode (); -     } -  +     //inserts a word into the trie. -     voidInsertstringword) { +trienode* temp =Root; A          for(inti =0; I < word.size (); i++){ at             if(Temp->childnode[word[i]-'a'] ==NULL) -Temp->childnode[word[i]-'a'] =NewTrienode (); -temp = Temp->childnode[word[i]-'a']; -         } -Temp->isval =true;//if the word is inserted, then Isval is true -     } in  -     //Returns If the word is in the trie. to     BOOLSearchstringword) { +trienode* temp =Root; -          for(inti =0; I < word.size (); i++){ the             if(temp = = NULL) Break; *temp = Temp->childnode[word[i]-'a']; $         }Panax Notoginseng         if(!temp)return false;//If the route does not exist, return false -         returnTemp->Isval; the     } +  A     //Returns If there is any word in the trie the     //That's starts with the given prefix. +     BOOLStartsWith (stringprefix) { -trienode* temp =Root; $          for(inti =0; I < prefix.size (); i++){ $             if(temp = = NULL) Break; -temp = Temp->childnode[prefix[i]-'a']; -         } the         if(temp) -             return true;//if it ' s the leaf node, return trueWuyi         Else  the             return false;//if it ' s not the leaf node, return false; -     } Wu  - Private: Abouttrienode*Root; $ }; -  - //Your Trie object would be instantiated and called as such: - //Trie Trie; A //Trie.insert ("somestring"); + //trie.search ("key");

Implement Trie (Prefix Tree)