Question

Scala: Write and test a program as elegantly as possible

You are given a puzzle like this:

7 __ 10 __ 2

Each blank may be filled with a ‘+’ (plus) or ‘-’ (minus), producing a value k. For all combinations of plus and minus, find the value of k that is closest to 0.

In the above case, there are 4 combinations, each producing a different value:

7 + 10 + 2 = 19 7 + 10 - 2 = 15 7 - 10 + 2 = -1 7 - 10 - 2 = -5

Of all these combinations, the value that is closest to zero is ​-1​. So the answer is -​ 1​. If there are more than one number that is closest, print the absolute value.

Sample Input/Output:

Enter digits: 7,10,2 Value close to zero is -1

Enter digits: 1,2,3,4 Value close to zero is 0

Answer 1

Solution:

import scala.math.abs

object Test {
    
    
    def closestToZero(values: Array[Int]): Int = {
        
        val possibleVals = List(values(0) + values(1) + values(2), values(0) + values(1) - values(2), values(0) - values(1) - values(2), values(0) - values(1)  + values(2))
        possibleVals.sortWith((x, y) => (abs(x) < abs(y)))(0)
    }
    
   def main(args: Array[String]) {
        val scanner = new java.util.Scanner(System.in)
        print("Enter digits: ")
        val vals = scanner.nextLine().split(",").map(_.toInt)
        
        print("Closest value is: " + closestToZero(vals))
   }
}