水仙花数lintcode

const getNarcissisticNumbers = function (n) {
        let num = 10 ** n - 1
        let arr = []
        for (let i = 10**(n-1); i <= num; i++) {
            let numstr = i.toString()
            let a = 0
            for (let j = 0; j <numstr.length; j++) {
                a+=Number(numstr[j]) ** n
                if (i === a) {
                    arr.push(i)
                }
            }
        }
        return arr
    }
    let a = getNarcissisticNumbers(3)
    console.log(a)