프로그래머스 / 가장 가까운 같은 글자

https://school.programmers.co.kr/learn/courses/30/lessons/142086

파이썬

def solution(s):
    marked = {}
    answer = []
    for index, letter in enumerate(s):
        answer.append(index - marked[letter] if letter in marked else -1)
        marked[letter] = index
    return answer

코틀린

class Solution {
    fun solution(s: String): IntArray {
        val answer = mutableListOf<Int>()
        val counter = mutableMapOf<Char, Int>()
        for ((index, each) in s.withIndex()) {
            answer.add(index - (counter[each] ?: (index + 1)))
            counter[each] = index
        }
        return answer.toIntArray()
    }
}

class Solution {
    fun solution(s: String): IntArray {
        val counter = mutableMapOf<Char, Int>()
        return s.withIndex().map { (index, each) ->
            val temp = counter[each]
            counter[each] = index
            if (temp == null) -1 else index - temp
        }.toIntArray()
    }
}

class Solution {
    fun solution(s: String) = s.withIndex()
        .map { (index, each) ->
            s.slice(0 until index)
                .lastIndexOf(each)
                .let { if (it == -1) -1 else index - it }
        }.toIntArray()
}