릿코드 451. Sort Characters By Frequency 코틀린

해시맵에 다떄려박고 해시맵을 value로 정렬해서 뽑아내서 리턴


정답

import java.util.LinkedList

class Solution {
    fun frequencySort(s: String): String {
        val strHashMap = hashMapOf<Char, Int>()
        for (i in s){
            strHashMap[i]=strHashMap[i]?.plus(1)?:1
        }
        val sortMap = sortMapByKey(strHashMap)
        println(sortMap)
        var res=""
        for ((key,value) in sortMap){
            for (j in 0 until  value){
                res+=key
            }
        }
        println(res)
        return res

    }
    fun sortMapByKey(map: Map<Char,Int>):LinkedHashMap<Char,Int>{
        val entries = LinkedList(map.entries)
       // entries.sortBy { it.value }
        entries.sortByDescending { it.value }
        val result = LinkedHashMap<Char, Int>()
        for(entry in entries) {
            result[entry.key] = entry.value
        }

        return result

    }
}