Interview question of the issue #259 of rendezvous with cassidoo.
Given an integer n, count the total number of 1 digits appearing in all non-negative integers less than or equal to n.
Example:
> numberOfOnes(14)
> 7 // 1, 10, 11, 12, 13, 14Just pnpm i to install all dependencies and then pnpm t to run the tests!