208. Implement Trie (Prefix Tree)

/**
 * Initialize your data structure here.
 */
// Mine
class Trie {
	constructor() {
		this.letters = {}
	}

	insert(word) {
		const len = word.length
		let curr = this.letters
		for (let i = 0; i < len; i++) {
			const letter = word[i]
			if (!curr[letter]) curr[letter] = {}
			curr = curr[letter]
		}
		curr.isEnd = true
	}

	traverse(word) {
		const len = word.length
		let curr = this.letters
		for (let i = 0; i < len; i++) {
			const letter = word[i]
			if (!curr[letter]) return false
			curr = curr[letter]
		}
		return curr
	}

	search(word) {
		return !!this.traverse(word).isEnd
	}

	startsWith(prefix) {
		return !!this.traverse(prefix)
	}
}
// https://leetcode.com/problems/implement-trie-prefix-tree/discuss/58965/Concise-JavaScript-solution
//ES5 Constructor function version
// function Trie() {
//   this.root = {}
// }

// Trie.prototype.insert = function(word) {
//   let curr = this.root
//   word.split('').forEach(ch => (curr = curr[ch] = curr[ch] || {}))
//   curr.isWord = true
// }

// Trie.prototype.traverse = function(word) {
//   let curr = this.root
//   for (var i = 0; i < word.length; i++) {
//     if (!curr) return null
//     curr = curr[word[i]]
//   }
//   return curr
// }

// Trie.prototype.search = function(word) {
//   let node = this.traverse(word)
//   return !!node && !!node.isWord
// }

// Trie.prototype.startsWith = function(word) {
//   return !!this.traverse(word)
// }

const trie = new Trie()
trie.insert('apple')
//Test cases
console.log(trie)
console.log(trie.search('app'))
console.log(trie.search('apple'))
console.log(trie.startsWith('app'))