func solution(_ s:String, _ n:Int) -> String { let upperStr = Array("abcdefghijklmnopqrstuvwxyz".uppercased()) let lowerStr = Array("abcdefghijklmnopqrstuvwxyz") var result = "" for i in s { // 대문자에 포함된 경우 if upperStr.contains(i) { var indexNum = (upperStr.firstIndex(of: i) ?? 0) + n if indexNum > 25 { indexNum = inde..