28. 수 조작하기 2

import Foundation

func solution(_ numLog:[Int]) -> String {
    
    var answer : String = ""
    
    for i in 0 ... numLog.count-2 {
        
        switch numLog[i+1] - numLog[i] {
            case 1 :
                answer += "w"
            case -1 :
                answer += "s"
            case 10 :
                answer += "d"
            case -10 :
                answer += "a"
            default :
            ""
        }
    }
    
    return answer
}