- it is turning the number into a string of 1s 3 => 111 4 => 1111 and so on
- then trying to simulate divisibility test by trying to find perfect groups of '11' to simulate division by 2 failing which (that is the backtracking part) and trying find perfect groups of '111' to simulate division by 3 and so on...
- then trying to simulate divisibility test by trying to find perfect groups of '11' to simulate division by 2 failing which (that is the backtracking part) and trying find perfect groups of '111' to simulate division by 3 and so on...
Clever but very inefficient