Exercism - Leap(With.Kotlin)

[문제]

 

Given a year, report if it is a leap year.

The tricky thing here is that a leap year in the Gregorian calendar occurs:

on every year that is evenly divisible by 4 except every year that is evenly divisible by 100 unless the year is also evenly divisible by 400

For example, 1997 is not a leap year, but 1996 is. 1900 is not a leap year, but 2000 is.

Notes

Though our exercise adopts some very simple rules, there is more to learn!

For a delightful, four minute explanation of the whole leap year phenomenon, go watch this youtube video.

 

[Solution1]

class Year(year: Int) {

    var isLeap: Boolean = false

    init {

        if(year % 400 != 0){
            if(year % 100 != 0){
                if(year %4 == 0){
                    isLeap = true
                }
            }
        }else{
            isLeap = true
        }

    }

}

테스트를 통과만 가능하도록 짠 부끄러운 코드

 

[Solution2]

class Year(year: Int) {
    val isLeap = checkLeap(year)

    private fun checkLeap(year: Int):Boolean {
        if(year % 400 == 0) return true

        if(year % 100 != 0 && year % 4 == 0) return true

        return false
    }
}

정리하여 나온 형태

 

[Solution3]

class Year(year: Int) {
    val isLeap = (year % 400 == 0) || (year % 100 != 0 && year % 4 == 0)
}

한줄로 요약해보라는 조언에 수정한 형태