Regex for Finding Radioactive Elements

Find the shortest regex that matches all radioactive elements and nothing else in the Periodic Table of Elements.

Radioactive Elements

'Technetium','Promethium','Polonium','Astatine','Radon','Francium','Radium','Actinium','Thorium','Protactinium','Uranium','Neptunium','Plutonium','Americium','Curium','Berkelium','Californium','Einsteinium','Fermium','Mendelevium','Nobelium','Lawrencium','Rutherfordium','Dubnium','Seaborgium','Bohrium','Hassium','Meitnerium','Darmstadtium','Roentgenium','Copernicium','Ununtrium','Flerovium','Ununpentium','Livermorium','Ununseptium','Ununoctium'

Non-radioactive Elements

'Hydrogen','Helium','Lithium','Beryllium','Boron','Carbon','Nitrogen','Oxygen','Fluorine','Neon','Sodium','Magnesium','Aluminium','Silicon','Phosphorus','Sulphur','Chlorine','Argon','Potassium','Calcium','Scandium','Titanium','Vanadium','Chromium','Manganese','Iron','Cobalt','Nickel','Copper','Zinc','Gallium','Germanium','Arsenic','Selenium','Bromine','Krypton','Rubidium','Strontium','Yttrium','Zirconium','Niobium','Molybdenum','Ruthenium','Rhodium','Palladium','Silver','Cadmium','Indium','Tin','Antimony','Tellurium','Iodine','Xenon','Caesium','Barium','Lanthanum','Cerium','Praseodymium','Neodymium','Samarium','Europium','Gadolinium','Terbium','Dysprosium','Holmium','Erbium','Thulium','Ytterbium','Lutetium','Hafnium','Tantalum','Tungsten','Rhenium','Osmium','Iridium','Platinum','Gold','Mercury','Thallium','Lead','Bismuth'

Scored by character count in the regex.
Use standard Perl regex (just no specialized functions).
Assume all lower case.
You only need to count the characters of the regex itself.

Note if you used a program to get you started and maybe post how well it did. I'll post my best attempt as an answer to get started/show an example.

qw3n

Posted 2014-01-08T21:31:34.413

Reputation: 733

@qw3n You could say “regular expression describing a regular language” to exclude all the language specific things. – FUZxxl – 2015-03-08T11:58:53.840

Can you quote a regex standard, such as POSIX regular, POSIX extended, PCRE…? Otherwise "language agnostic" doesn't really mean much. – Tobia – 2014-01-08T21:55:29.727

Sorry, I have only had to use regex in java and javascript and don't really know all the differences. The goal is to create a regex that would work in most common languages without relying on language specific feature. – qw3n – 2014-01-08T22:02:06.473

There is an ongoing discussion as to whether we want regex golf on this site. Please contribute.

– Peter Taylor – 2014-01-08T23:48:09.913

Answers

Char count 59

e.+[hktv]|oh?r.+m|p...?o|r.*ci|be?.i|^c?u|rad|sta|has|ct|fe

Found via a mix of manually selecting good parts and running Peter Norvig's golfer on the remaining items.

Regex101 link

Sp3000

Posted 2014-01-08T21:31:34.413

Reputation: 58 729

LOL accepted answer after over 2 years! Imagine that @drjimbob's answer was the previous accepted answer. *3 characters better than accepted answer!*

– Erik the Outgolfer – 2016-05-31T18:28:25.757

For pete's sake! I've had the best answer for more than a year, and then I make it even better, and then you come along and do even better and get accepted! – EMBLEM – 2016-06-01T01:30:16.130

Char Count 61

lon|ct|oh|^ra|...t.+i|^c?u|or.+u|r.+c.|e..+e|f.?e|^h?as|be*.i

~~One~~ 3 characters better than accepted answer!

63-character solution found with Peter Norvig's Regex golf solver. 61-character improvement found by a personal rewrite of that program in Go.

EMBLEM

Posted 2014-01-08T21:31:34.413

Reputation: 2 179

Char count 64

^(c?u|ra|no)|e.[kht]|[^l][gecv]i|[^c]oh?[rn]iu|f.r|ac|sta|bn|has

Should note, used parts of qw3n solution to reduce down my solution. Also used Peter Taylor's suggestion to trim two characters.

dr jimbob

Posted 2014-01-08T21:31:34.413

Reputation: 336

I have a feeling this is pretty near if not an optimal solution. Wish I'd seen that f.r part. :) – qw3n – 2014-01-10T01:05:40.493

1There's an easy 1-char saving by grouping everything anchored on ^, and another by changing ^(u|cu|...) into ^(c?u|...) – Peter Taylor – 2014-01-10T09:46:19.537

Char count 69

^u|e.[kht]|[^l][gecv]i|[^c]oh?[rn]iu|^cu|f[oe]|a[cds]t|has|nob|rad|du

Curium/Cerium are a pain to deal with

qw3n

Posted 2014-01-08T21:31:34.413

Reputation: 733