Minimum sum of squares of cha.racter counts in a given string after removing k characters

DS_ALGO_Strings_002.kt

import kotlin.system.*
import kotlin.contracts.*
import java.util.*

fun main() {
    print(MinCharSquareSum().getResult("aabaa", 0))
}

class MinCharSquareSum {
   
    fun getResult(input : String, k: Int): Int{
        
        val strLength = input.length
        
        if(k >= strLength){
            return 0
        }
        
        fun result() : Int{
            
            fun calculateFrequency(): IntArray{
                val arr = IntArray(26)
                
                for(i in 0 until strLength){
                    arr[input.get(i) - 'a']++
                }
                
                return arr
            }
            
            fun calculatePriority() : PriorityQueue<Int>{
                val f = calculateFrequency()
                val p = PriorityQueue(IntCompare())
                
                for (i in 0 until f.size) if(f[i] != 0) p.add(f[i])
                
                return p
            }
            
            val p = calculatePriority()
            
            for(i in 0 until k){
                var temp = p.peek()
                p.poll()
                temp -= 1
                p.add(temp)
            }
            
            var res = 0
            
            while(p.isNotEmpty()){
                var temp = p.peek()
                res += temp * temp
                p.poll()
            }
            
            return res
        }
        
        return result()
    }
    
    inner class IntCompare : Comparator<Int>{
        
        override fun compare(prev: Int, next: Int): Int{
            return when{
                prev > next -> -1
                prev < next -> 1
                else -> 0
            }
        }
    }
    
}