프로그래머스 - 가장 가까운 글자 [JS]

solution("banana")

 

if 이후-> overlap : ['b','a','n']

else{

[1] : overlap.length=3 overlap.lastIndexOf(s[i])=1 -> overlap.push(s[i]) = 'a'

overlap : ['b','a','n','a']

[2] : overlap.length=4 overlap.lastIndexOf(s[i])=2

[3] : overlap.length=5 overlap.lastIndexOf(s[i])=3

 

lastIndexOf를 사용함으로써 가장 위쪽의 있는 글자와 비교를 하기 위해서

function solution(s) {
  let overlap=[]
  let res=[]
  for (const i in s) {
    if(!overlap.includes(s[i])){
      overlap.push(s[i])
      res.push(-1)
    }
    else{
      res.push(overlap.length-overlap.lastIndexOf(s[i]))
      overlap.push(s[i])
    }
  }
  return res
}