Only problem for me is that method .delete_if mutates the caller.
Value of "order" was changed. Method .reject would suit me be better in this case.

Nevertheless great solution!

I like this solution because it's simple to me to understand. Much more simply than some solutions above. Thanks!

It is probably faster because the current best (map) generate a range and iterates over it replacing each element while this just generates a enumberable/array.

Now that is concise!

like my solution http://www.codewars.com/kata/reviews/554cea21085cd84f27000062/groups/555efbbfab6b61af960000bf

best

It's usable!

I'm humbled by this solution and I have learned much from it.

Really nicely concise. :)
The same algorithm as many others (myself included), but it looks really nice like this.