题解 | #字符串加解密#

1. 思路很简单啦，就是按题目要求给出了加解密的函数；
2. str.charCodeAt(0)可以获得ascii码；String.fromCharCode()可以由Ascii码获得字符
3. 我一开始算错了，我记得A的ascii码是65，然后算Z是65+26==91，但其实是90

function addPassword (str) {
//     创建一个数组接收加密后的字符
    let arr = new Array(str.length).fill(-1)
    for (let i = 0; i < str.length; i++) {
        let code = str[i].charCodeAt(0)
        if (code >= 65 && code <= 89) {
            arr[i] = (String.fromCharCode(code + 33))
        } else if (code >= 97 && code <= 121) {
            arr[i] = (String.fromCharCode(code - 31))
        } else if (parseInt(str[i]) >= 0 && parseInt(str[i]) <= 9){
            arr[i] = ((parseInt(str[i]) + 1) % 10)
        } else if (code === 90) {
            arr[i] = ('a')
        } else if (code === 122) {
            arr[i] = ('A')
        }
    }
    return arr.join('')
}

function unPassword (str) {
    //     创建一个数组接收加密后的字符
    let arr = new Array(str.length)
    for (let i = 0; i < str.length; i++) {
        let code = str[i].charCodeAt(0)
        if (code >= 66 && code <= 90) {
            arr[i] = (String.fromCharCode(code + 31))
        } else if (code >= 98 && code <= 122) {
            arr[i] = (String.fromCharCode(code - 33))
        } else if (parseInt(str[i]) >= 0 && parseInt(str[i]) <= 9){
            arr[i] = ((parseInt(str[i]) + 9) % 10)
        } else if (code === 65) {
            arr[i] = ('z')
        } else if (code === 97) {
            arr[i] = ('Z')
        }
    }
    return arr.join('')
}

console.log(addPassword(readline()))
console.log(unPassword(readline()))