The lighthouse in binary

Problem

When fog rolls in, the Grey Point lighthouse talks to ships in flashes: a long one is a 1 and a short one is a 0. That way it sends numbers in binary, and the keeper asks you to get each message ready.

Write a function that takes a whole number, 0 or greater, and returns it written in binary as a string of zeros and ones. It is a string, not a number: for 13 you return "1101", not the number 1101.

You get it by dividing by 2 until you reach 0, and each remainder is a digit: 13 divided by 2 is 6, remainder 1; 6 by 2 is 3, remainder 0; 3 by 2 is 1, remainder 1; 1 by 2 is 0, remainder 1. Read the remainders from last to first and you get 1101.

No leading zeros, and 0 is written "0".

Examples

• The example

  13 → "1101"

• One

  1 → "1"

• Ends in zero

  6 → "110"

• Eight ones

  255 → "11111111"

Besides these, the challenge has hidden tests that are revealed when you submit your solution.

You start with this

def to_binary(n):
    pass

function toBinary(n) {
}