Where to get good algorithm problem with solutions

Question

Hi all,

I know some algorithm judge online system, but few of them have the solution attached. Most of the time after I deliever my own answer on those system, I can seen other people's solution have fewer memory usage and shorter CPU time cost which after refactories my code can not achieve. Is there any problem set have elegant solutions with them? I wanna to read the solution to find where to fill the gap. Thanks in advance!

Answer 1

TopCoder has tons of problems and solutions done in contests.

Answer 2

You can also check out the Google Code Jam. Also, for most popular online judges (e.g. UVa, SPOJ), a searching the forum or just searching at google turns up a lot of ideas and hints.

Answer 3

FWIW, CodeChef has some really interesting problems. You can code up the solution and submit it to be tested against their test cases. Its fun actually.