I got solutions on internet but it is quite difficult to understand. Plz can someone explain this.

You are given an integer N. You have to find smallest multiple of N which consists of digits 0 and 1 only. Since this multiple could be large, return it in form of a string.

Note: - Returned string should not contain leading zeroes.

For N = 55, 110 is smallest multiple consisting of digits 0 and 1. For N = 2, 10 is the answer.