I wrote a tool 'Datagen' using C++. It's a command-line tool, targeted at CPers.

Using a single-line command, you can generate testcase in batches.

For example, if you want to generate #11-#20 testcases for your problem, with a time limit of 1.5s, and compare the running time with brute force solution as well:

datagen <yourproblem> 11..20 -h -t 1500

You can find more here.