soobing.ts

// 3rd tried
class TrieNode {
  children: Map<string, TrieNode>;
  isEnd: boolean;
  constructor() {
      this.children = new Map();
      this.isEnd = false
  }
}
class Trie {
  root: TrieNode;

  constructor() {
      this.root = new TrieNode();
  }

  insert(word: string): void {
      let node = this.root;
      for(const ch of word) {
          if(!node.children.has(ch)) {
              node.children.set(ch, new TrieNode());
          }
          node = node.children.get(ch)!
      }
      node.isEnd = true;
  }

  search(word: string): boolean {
      let node = this.root;
      for(const ch of word) {
          if(!node.children.has(ch)) return false;
          node = node.children.get(ch)!;
      }
      return node.isEnd;
  }

  startsWith(prefix: string): boolean {
      let node = this.root;
      for(const ch of prefix) {
          if(!node.children.has(ch)) return false;
          node = node.children.get(ch)!;
      }
      return true;
  }
}

/**
* Your Trie object will be instantiated and called as such:
* var obj = new Trie()
* obj.insert(word)
* var param_2 = obj.search(word)
* var param_3 = obj.startsWith(prefix)
*/