Interview question by Cassidy Williams (2019-12-16 newsletter)

binaryQueue.js

/*
  Given a positive number N, generate binary numbers between 1 to N
  using a queue-type structure in linear time.
*/

function binaryQueue(x) {
    return [...Array(x).keys()]     // let's build an array of numbers from 0 to x
        .slice(1)                   // drop the first element to have an array from 1 to x
        .map(k => k.toString(2))    // now we have an array of binaries from 1 to x as strings
        .map(e => parseInt(e, 10))  // now we have an array of numbers from 1 to x in binaries
        .join(" ")                  // let's have the final touch :)
}

console.log(binaryQueue(10)); // here is a simple exemple