On: Regex Golf

[easy_rider]

(.+|)foo(.+|)

Lol so awesome this. I oblige. Much love!

[ryanthejuggler → easy_rider]

Powers:

    ^((((((((((x)\10?)\9?)\8?)\7?)\6?)\5?)\4?)\3?)\2?)\1?$

I feel like there's gotta be a sneakier way of doing this.

[XaspR8d → ryanthejuggler]

Completely not sneaky at all, but does reasonably well at 71 points:

  ^(x|xx|xxxx|x{8}|x{16}|x{32}|(x{64})+)$

[rplnt → ryanthejuggler]

Mine is a bit shorter, though a bit more "meh" as well.

    ^x{32}$|^(x{2}){1,8}$|^(x{64})+$|^x$

[galen_tyrol → rplnt]

improved, gives 80

    ^(x|(xx){1,9}|x{32}|(x{64})+)$

[rplnt → galen_tyrol]

I tried to get rid of those redundant ^ and $ but it somehow didn't work. I probably forgot to put it all inside one group.

[alanh → rplnt]

They are not redundant. Any string of one or more exes is going to constrain a substring of exes of length 2^n (consider n=0 for a trivial proof), so you do need those anchors!

[rplnt → alanh]

I meant my previous post where I had them in every single possibility.

[cleaver → ryanthejuggler]

I did similarly, but managed to squeeze out a few more points:

^(((((((((xx?)\9?)\8?)\7?)\6?)\5?)\4?)\3?)\2?)\1?$

(60 points)

[willchang → ryanthejuggler]

A non-cheating solution, 79 points.

  ^((xx?|xxxx)(\2{7})?)(\1{63})?$

[danielweber → ryanthejuggler]

I was working on this pattern:

^(x{1,2}){1,2}$

But it wedged my browser as I started adding more terms. :/

[delluminatus → ryanthejuggler]

58 points:

    ^x$|^(x+)\1$