시저 암호

https://school.programmers.co.kr/learn/courses/30/lessons/12926

// 1차
function solution(s, n) {
    return s.split("").map(str=>{
        const unicode = str.charCodeAt(0)
        if (unicode===32) {
            return " "
        }
        else if (unicode>=65 && unicode<=90) {
            if (unicode+n > 90) {
                return String.fromCharCode(unicode+n-26)
            }
            return String.fromCharCode(unicode+n)
        } else {
            if (unicode+n > 122) {
                return String.fromCharCode(unicode+n-26)
            }
            return String.fromCharCode(unicode+n)
        }
    }).join("")
}

2차
function solution(s, n) {
    return s.split("").map(str=>{
        const unicode = str.charCodeAt(0)
        if (unicode===32) {
            return " "
        } else if ((unicode<=90 && unicode+n > 90) || unicode+n > 122) {
            return String.fromCharCode(unicode+n-26)
        } else {
            return String.fromCharCode(unicode+n)
        }
    }).join("")
}