Look up "Introduction to Algorithms: A Creative Approach" by Manber and "Algorithm Design Manual" by Skiena. The former has the best exercises (borderline math

Look up "Introduction to Algorithms: A Creative Approach" by Manber and "Algorithm Design Manual" by Skiena. The former has the best exercises (borderline mathematical), but is lightest on implementation. The latter has the best introductory pedagogy and has implementation code, but is not what I would use if I want to grok algorithms deeply. People keep recommending Cormen. He's the book you get AFTER you understand algorithms. Cormen reads more like a reference manual. Cormen can substitute in for Skiena in a pinch. Skiena sounds like the one you want most of all though.