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Feature #2: Design Search Autocomplete System

Sumit Rawal answered on May 24, 2023 Popularity 3/10 Helpfulness 1/10

answer Feature #2: Design Search Autocomplete System

Feature #2: Design Search Autocomplete System

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import scala.collection.mutable.ArrayBuffer
import scala.collection.mutable.HashMap
import scala.math.Ordered.orderingToOrdered;


class Node() extends Comparable[Node] {
  var children: HashMap[Character, Node]  = new HashMap[Character, Node]()
  var isEnd:Boolean = false
  var rank:Int = 0
  var data: String = null
  var hot: ArrayBuffer[Node] = new ArrayBuffer[Node]

  override def compareTo(n: Node): Int = {
    if (this.rank == n.rank)
      return this.data.compareTo(n.data)
    n.rank - this.rank
  }

  def update(n: Node): Unit = {
    if (!this.hot.contains(n))
      hot += n
    hot.sortWith(_ < _)
    if (hot.size > 3)
      hot.remove(hot.size - 1)
  }
}

class AutocompleteSystem(val sentences: Array[String], val times: Array[Int]) {
  private var root:Node = new Node
  private var current:Node = root
  private var keyword:String = ""

  for (i <- 0 until sentences.length) {
    this.addRecord(sentences(i), times(i))
  }



  def addRecord(sentence: String, t: Int): Unit = {
    var node:Node = this.root
    val visited = new ArrayBuffer[Node]
    for (c <- sentence.toCharArray) {
      if (!node.children.contains(c))
        node.children(c) = new Node
      node = node.children(c)
      visited += node
    }
    node.isEnd = true
    node.data = sentence
    node.rank += t

    for (i <- visited) {
      i.update(node)
    }
  }

  def autoComplete(c: Char): ArrayBuffer[String] = {
    val res = new ArrayBuffer[String]
    if (c == '#') {
      addRecord(keyword, 1)
      keyword = ""
      current = root
      return new ArrayBuffer[String]
    }
    this.keyword += c
    if (current != null) {
      if (!current.children.contains(c))
        return new ArrayBuffer[String]
      else
        current = current.children(c)
    } else
      return new ArrayBuffer[String]
    //import scala.collection.JavaConversions._
    for (node <- current.hot) {
      res += node.data
    }
    return res
  }
}

object Solution {

  def printArrayBuffer(arr:ArrayBuffer[String]):Unit={
    if(arr.size>0)
      for(s <- arr)
        print(s)
    else
      print(" ")
    println()
  }

  def main(args: Array[String]): Unit = {
    val sentences = Array("beautiful", "best quotes", "best friend", "best birthday wishes", "instagram", "internet")
    val times = Array(30, 14, 21, 10, 10, 15)
    val auto = new AutocompleteSystem(sentences, times)
    printArrayBuffer(auto.autoComplete('b'))
    printArrayBuffer(auto.autoComplete('e'))
    printArrayBuffer(auto.autoComplete('s'))
    printArrayBuffer(auto.autoComplete('t'))
    printArrayBuffer(auto.autoComplete('#'))
  }
}

Popularity 3/10 Helpfulness 1/10 Language scala

Source: Grepper

Tags: autocomplete scala search system

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Contributed on May 24 2023

Sumit Rawal

0 Answers Avg Quality 2/10

Feature #2: Design Search Autocomplete System

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