Programmers Kotlin 문제 풀이 11 ~ 20

짝수와 홀수
https://school.programmers.co.kr/learn/courses/30/lessons/12937

class Solution {
    fun solution(num: Int): String {
        return if(num % 2 == 0) "Even" else "Odd"
    }
}

평균 구하기

https://school.programmers.co.kr/learn/courses/30/lessons/12944

class Solution {
    fun solution(arr: IntArray): Double {
        return arr.average()
    }
}

자릿수 더하기
https://school.programmers.co.kr/learn/courses/30/lessons/12931

class Solution {
    fun solution(n: Int): Int {
        var sum = 0
        
        for(i in n.toString()) {
            sum += i.toString().toInt()
        }
        
        return sum
    }
}

약수의 합
https://school.programmers.co.kr/learn/courses/30/lessons/12928

class Solution {
    fun solution(n: Int): Int {
        var sum = 0
        
        for(i in 1..n) {
            if(n % i == 0) sum += i
        }
        
        return sum
    }
}

나머지가 1이 되는 수 찾기
https://school.programmers.co.kr/learn/courses/30/lessons/87389

class Solution {
    fun solution(n: Int): Int {
        var result = 0
        
        for(i in 1..n) {
            if(n % i == 1) {
                result = i
                break
            }
        }
        
        return result
    }
}

x만큼 간격이 있는 n개의 숫자
https://school.programmers.co.kr/learn/courses/30/lessons/12954

class Solution {
    fun solution(x: Int, n: Int): LongArray {
    
        val list = LongArray(n)
        
        for (i in 1..n) {
            list[i - 1] = (i * x.toLong())
        }
        
        return list
    }
}

자연수 뒤집어 배열로 만들기
https://school.programmers.co.kr/learn/courses/30/lessons/12932

class Solution {
    fun solution(n: Long): IntArray {
        return n.toString().reversed().map { it -> it.toString().toInt() }.toIntArray()
    }
}

문자열을 정수로 바꾸기
https://school.programmers.co.kr/learn/courses/30/lessons/12925

class Solution {
    fun solution(s: String): Int {
        return s.toInt()
    }
}

정수 제곱근 판별
https://school.programmers.co.kr/learn/courses/30/lessons/12934

• sqrt : 제곱근 (인수, 반환 타입 : Double)
• pow : 제곱 수 (인수, 반환 타입 : Double)

import kotlin.math.pow
import kotlin.math.sqrt

class Solution {
    fun solution(n: Long): Long {
        
    val result = sqrt(n.toDouble()).toInt().toDouble()
    
    if(result.pow(2) == n.toDouble()) return (result + 1).pow(2).toLong() else return -1
    }
}

 

정수 내림차순으로 배치하기

https://school.programmers.co.kr/learn/courses/30/lessons/12933

class Solution {
    fun solution(n: Long): Long {
        return n.toString().toList().sorted().reversed().joinToString(separator = "").toLong()
    }
}