Computer Science

• Algorithm Design, Kleinberg & Tardos
• Algorithms, Papadimitriou, Dasgupta & Vazirani
• Introduction to Algorithms, Cormen, Leiserson, Rivest & Stein

Mathematics

• Mathematicial Circles, Fomin, Genkin & Itenberg
• Introductory Combinatorics, Richard A. Brualdi
• Probability for the Enthusiastic Beginner, David Morin
• Bridge To Higher Mathematics, Sam Vandervelde
• Discrete Mathematics, Kenneth Rosen

Software

• C++ Primer (v.5), Lippman & Lajoie
• Programming Pearls, Jon Bentley