Question

How to find a number in array that appears once in Scala

Answer 1

object SingleNumberFinder {
  def numberExistsFewTimes(arr: Array[Int], number: Int, index: Int): Boolean = {
    var exist = false
    
    for (i <- arr.indices) {
      if (arr(i) == number && i != index) {
        exist = true
      }
    }
    
    exist
  }

  def getSingleNumber(arr: Array[Int]): Int = {
    var singleNumber = -1
    
    for (i <- arr.indices) {
      if (!numberExistsFewTimes(arr, arr(i), i)) {
        singleNumber = arr(i)
      }
    }
    
    singleNumber
  }

  def main(args: Array[String]): Unit = {
    val arr = Array(3, 2, 1, 2, 3, 3, 1, 5, 9, 7, 7, 9, 9)
    
    println(getSingleNumber(arr))
  }
}
 
 
    
/*
run:
    
5
    
*/

 

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