Coding Challenges - Dlang or Generic

[Paul via Digitalmars-d-learn]

Greetings Dlang-ers
I was wondering if anyone knew of any coding challenges available 
where the input and output are specified and its left to the 
programmer to find a solution?  Free would be nice but even paid 
services would be worth considering.  I'm taking a D class right 
now and it has little challenges in the lessons where much of the 
work is done for you, but I'm thinking of a site/service that is 
dedicated to these types of challenges (without doing any work 
for you).

I wonder if a site dedicated to Dlang challenges would 'fly'?  It 
would be quite interesting and instructive to see how different 
coders solved a particular coding problem.  Statistics could be 
generated for each solution (e.g. compile time, execution time, 
source code size, executable size, @safe, @nogc, readability of 
source code, helpfulness of comments, etc.).  With D's 
multi-paradigm power it could be fascinating.  I know.  Someone's 
going to say why don't YOU do it:)

regards,