Khan/khan-exercises — pull request #12702 by spicyj (2012-02-01 02:37:21+00:00)
Title: "Smarter" comma checking

You can check my regex here:

http://regexpal.com/?flags=m®ex=%5E(%5B%2B-%5D%3F(%3F%3A%5Cd%7B1%2C3%7D(%3F%3A%5B%2C%20%5D%3F%5Cd%7B3%7D)*%5C.%3F%7C%5Cd%7B0%2C3%7D(%3F%3A%5B%2C%20%5D%3F%5Cd%7B3%7D)*%5C.(%3F%3A%5Cd%7B3%7D%5B%2C%20%5D%3F)*%5Cd%7B1%2C3%7D))%24&input=1%0A12%0A123%0A1234%0A1%2C234%0A12%2C34%0A1234%2C%0A%0A12345%0A1%2C2345%0A12%2C345%0A123%2C45%0A%0A123%2C456%0A123456%0A%0A12345678%0A12%2C345%2C678%0A12%2C345678%0A12345%2C678%0A12%20345%20678%0A%0A.%0A0.0%0A.2%0A.2315312412%0A11.124%20567%0A.123%20456%0A1%2C234.5678