Years ago when I was in school my computer science department used a website that had many different problem solving questions typically used in computer programming. They were ordered in difficulty and you were presented the solution after you attempted the problem. The site was used in competitions and was very useful for training purposes. Since I am trying to brush up on my algorithm skills, a good tool like this would be very useful. Does anyone know of a site similar to this in "modern" times?
closed as not constructive by gnat, MainMa, Walter, Robert Harvey, Ryathal Nov 2 '12 at 20:05
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You should definitely check out Project Euler.
While the problems are not perfectly ordered in difficulty, they do tend to get harder as you work your way up.