Algorithms, Part I
Princeton's Robert Sedgewick and Kevin Wayne teach the essential algorithms and data structures every serious programmer needs, with heavy emphasis on Java implementations and scientific performance testing. Thirteen modules cover union-find, elementary sorts, mergesort, quicksort, priority queues, binary search trees, and hash tables, backed by 54 videos and programming assignments like Percolation, Collinear Points, and an 8 Puzzle solver graded by an autograder that checks style, correctness, and efficiency. Coursera states plainly that all features of this course are free and that Princeton policy means no certificate is issued for it at all. The course pairs with the textbook Algorithms, Fourth Edition, though the book is optional extra reading rather than required. Interview-style practice questions after each module let you rehearse the kind of algorithm explanations that come up in technical interviews.