릿코드 881. Boats to Save People 코틀린

해시맵에 다 때려박고,큰값부터 넣고,리미트에 자기뺀거중 가장 큰값도 -1후 res+1


정답

class Solution {
    fun numRescueBoats(people: IntArray, limit: Int): Int {
        val sortPeople = people.sorted()
        var res=0
        val peopleMap = hashMapOf<Int, Int>()
        for (i in sortPeople){
            peopleMap[i]=peopleMap[i]?.plus(1)?:1
        }
        while (peopleMap.isNotEmpty()){
            val tempMax = peopleMap.keys.max()
            res+=1
            peopleMap[tempMax]=peopleMap[tempMax]!!-1
            if (peopleMap[tempMax]==0){
                peopleMap.remove(tempMax)

            }
            val otherLimit = limit - tempMax
            val outer = peopleMap.keys.firstOrNull() { it <= otherLimit }
            if (outer==null){
                continue
            }
            peopleMap[outer]=peopleMap[outer]!!-1
            if (peopleMap[outer]==0){
                peopleMap.remove(outer)
            }

        }
        return res
    }
}

 

 

그냥 제일큰거랑 제일작은거랑 두개 더해서 리미트보다 크면 큰거만 리스트에서 제거하는거 반복하는게 시간복잡도도 낮고 더 편하긴했겠다 생각해보니