I'd like to inform you that on 30th of June on Coursera will start second session of Tim Roughgarden's "Algorithms: Design and Analysis, Part 1" course. I took first session of this course a couple of years ago, in fact this is a source of my initial knowledge about algorithms and data structures and I started taking part in competitive programming contests soon after finishing second part of the course. I would definitely recommend taking it, I'd say that it should be interesting and useful for CF green & blue rating zone coders. The course consists of video lectures, quizzes and programming assignments (it's not a pure theory class) and will take approximately 4-8 hours per week to finish it successfully.

To give you an idea on topics covered by this course, let me just copy the course syllabus here:

Week 1: Introduction. Asymptotic analysis including big-oh notation. Divide-and-conquer algorithms for sorting, counting inversions, matrix multiplication, and closest pair.

Week 2: Running time analysis of divide-and-conquer algorithms. The master method. Introduction to randomized algorithms, with a probability review. QuickSort.

Week 3: More on randomized algorithms and probability. Computing the median in linear time. A randomized algorithm for the minimum graph cut problem.

Week 4: Graph primitives. Depth- and breadth-first search. Connected components in undirected graphs. Topological sort in directed acyclic graphs. Strongly connected components in directed graphs.

Week 5: Dijkstra's shortest-path algorithm. Introduction to data structures. Heaps and applications.

Week 6: Further data structures. Hash tables and applications. Balanced binary search trees.

There is a second part of this course as well which covers greedy algorithms, dynamic programming and NP hard problems, I would recommend taking it as well but it turns out that there was a session of it which finished recently, I don't know when they will schedule the next one but I guess you can still watch the lectures.