Tries: Contacts solution

gistfile1.txt

class Node {
  constructor(word, index = 0) {
    this.count = 0
    this.children = new Map()
    
    if (word) { // Could be undefined
      this.symbol = word[index]
      this.completeWord = ((word.length - 1) === index)
      
      if (!this.completeWord) {
        this.insert(word, index + 1)
      } else {
        this.count += 1
      }
    }
  }

  insert(word, index = 0) {
    this.count += 1
    
    if (word.length === index) {
      return false
    }

    const symbol = word[index]
    
    if (this.children.has(symbol)) {
      this.children.get(symbol).insert(word, index + 1)
    } else {
      this.children.set(
        symbol,
        new Node(word, index)
      )
    }
  }

  getNode(word, index = 0) {
    const symbol = word[index]
    const nextIndex = index + 1
    
    if (this.children.has(symbol)) {
      return this.children.get(symbol).getNode(word, nextIndex)
    } else if (word.length === index) {
      return this
    } else {
      return null
    }
  }

  getCount() {
    return this.count
  }
}