[indigochill]

If you prefer watching videos/working through a MOOC for this stuff, I can highly recommend Robert Sedgewick's Algorithms I on Coursera: https://www.coursera.org/learn/algorithms-part1

If you don't know his name, you should - he's written some of the best books on these algorithms and his MOOC is similarly rich in visualizations and concrete examples that help you develop the intuition for the algorithms. Also incidentally his doctoral advisor was Donald Knuth, who he evidently learned a lot from.