HALT in the name of the law This is an idea for a cops-and-robbers challenge based on the halting problem. Cops You must write a program P that takes as input programs in some language L. It should attempt to output a truthy value if its input program ever halts, and a falsy value if it doesn'...

The Most Complex Chinese Character code-golf kolmogorov-complexity graphical-output Challenge Supplied a size by the user, you must output the Chinese character for biáng. The size is the length of the side of the svg supplied below. Your program must not access any external sources and must r...

Monkeys at a Typewriter code-challenge Sometimes when you press a key on a keyboard, the letter doesn't always display on screen. Whether this is because of a dodgy connection or otherwise, you have decided to write a script to control the probability of a letter displaying on screen when the c...

Coprime Factorization of the Least Common Multiple code-golf math number-theory Given any (ordered) pair of integers (a, b), it's possible to write their least common multiple1 as a product c · d of two coprime divisors of a and b, respectively. For example, consider the pair (12, 18); the leas...