Node.js)백준 1212번: 8진수 2진수

https://www.acmicpc.net/problem/1212

1212번: 8진수 2진수

const fs = require('fs');
let N = fs.readFileSync("./dev/stdin").toString().trim().split('');
let answer = '';

const bin ={
  '0':'000',
  '1':'001',
  '2':'010',
  '3':'011',
  '4':'100',
  '5':'101',
  '6':'110',
  '7':'111',
}
const first = {
  '0':'0',
  '1':'1',
  '2':'10',
  '3':'11',
  '4':'100',
  '5':'101',
  '6':'110',
  '7':'111',
}

while(N.length>1){
  answer = bin[N.pop()]+answer
}

console.log(first[N.pop()]+answer)