Question

How to remove odd frequency characters from a string in Scala

Answer 1

import scala.collection.mutable

object Main {
  def removeOddFrequencyCharacters(s: String): String = {
    val frequencyMap = mutable.HashMap[Char, Int]()
    val chArray = s.toCharArray

    // Count the frequency of each character
    for (ch <- chArray) {
      frequencyMap(ch) = frequencyMap.getOrElse(ch, 0) + 1
    }

    // Build the result string excluding characters with odd frequencies
    val result = new StringBuilder
    for (ch <- chArray) {
      if (frequencyMap(ch) % 2 == 0) {
        result.append(ch)
      }
    }

    result.toString()
  }

  def main(args: Array[String]): Unit = {
    var s = "scala programming version 3.3.4"

    s = removeOddFrequencyCharacters(s)

    println(s)
  }
}



/*
run:
  
sogmmingsion3.3.

*/

 

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