Practical tips debugging deep recursion?

Question

I\'m working on a board game algorithm where a large tree is traversed using recursion, however, it\'s not behaving as expected. How do I handle this and what are you experience

Answer 1

I know what a pain this can be. At my job, we are currently working with a 3rd party application that basically behaves as a black box, so we have to devise some interesting debugging techniques to help us work around issues.

When I was taking a compiler theory course in college, we used a software library to visualize our trees; this might help you as well, as it could help you see what the tree looks like. In fact, you could build yourself a WinForms/WPF application to dump the contents of your tree into a TreeView control--it's messy, but it'll get the job done.

You might want to consider some kind of debug output, too. I know you mentioned that your tree is large, but perhaps debug statements or breaks at key point during execution that you're having trouble visualizing would lend you a hand.

Bear in mind, too, that intelligent debugging using Visual Studio can work wonders. It's tough to see how state is changing across multiple breaks, but Visual Studio 2010 should actually help with this.

Unfortunately, it's not particularly easy to help you debug without further information. Have you identified the first depth at which it starts to break? Does it continue to break with higher search depths? You might want to evaluate your working cases and try to determine how it's different.