[xchkr1337]

Just picking digits from the diagonal might not work, you have to make sure the digits of the new number aren't equal to the ones on the diagonal, one way is to add 1 mod 10, in the case you showed it would result with 0.209...

[pfortuny]

Also (this is a very very minor detail) it is best to inly consider numbers without the digit eight. Otherwise you might end up with 0.99999999 which is one.

This is the tiniest of details but important for precision.

[IIAOPSW]

thanks, I fucked up the easy part lol