If you want to work for Microsoft or Google, while you likely can't get away with using your employers's $2K, the best books to read are Cracking the Coding Interview and Elements of Programming Interviews. Both books have very solid algorithm questions which you can use to go research the various algorithms and learn them. Although, I'd wait for Elements of Programming Interviews v2 which will include Java samples, as opposed to C++, but that's just me. McDowell's The Google Resume also has some useful tidbits in it.
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