# March 27, 2019 Water Cooler: My Favourite Algorithm Forum Threads on Topcoder

Algorithm forums of Topcoder are where some of the brightest minds come to discuss the algorithms, approaches and solutions they stumble upon. Here are ten interesting threads that are my favourite, and I think any programmer would benefit from reading.

Top Ten Algorithm and Marathon Match Threads:

- Want to learn how to do a depth first search? One of the best recipes to do the DFS can be found on Topcoder! The DFS is then applied to two of the practice problems.
- Another thread discusses how to work through a line sweep. All the points in a line sweep are processed for a fixed set of X. The problem applies line sweep for multiple problems.
- The following thread deals with convex hull and its application to the problem, ExtendableTriangles. The convex hull discusses two different applications for the problem: Jarvis’s march or Graham’s scan. It finds a convex polygon with minimal possible area. Three points are not allowed to be on the same line.
- The following algorithm match forum is from SRM 309. At the conclusion of SRM 309, the problem, SynchronizingGuideposts, drew some confusion from some of the Topcoder members. The problem solvers were collectively able to understand how to solve the problem by iterating through all the points of interest and selecting the lowest costing distance. There is also a discussion about which language allows for optimization for the problem to be solved accurately and quickly (The best language is C++.).
- The following algorithm match forum post is from SRM 739. Matijaman discusses whether to use Haskell versus C++ to solve problems. For readability, Haskell is preferable. However, C++ tends to be easier to optimize and faster.
- Simulated annealing is a NP-hard problem that is often explored in Topcoder challenges. This recipe talks about how to handle different types of mutations, generation, delta, and perturbating the solution. The recipe is applied to three Topcoder Open problems.
- What is the best language to program in for the Topcoder competitive problems? Based on the Formula One World Championship Competition, this forum states that the solutions that are written in C++ and Java consistently place first.
- For Marathon Match 109, this forum talks about the constraint on the number of edges and the constraint on the complexity of the algorithm. The challenge is currently running, so be sure to participate!
- Topcoder is currently running the Quantum Computing Challenge Series – Max Cut Marathon Challenge. One of the forums related to the challenge talks about how to perform a non-redundant cut for finding the maximum number of cuts in the graph. It also clarifies the number of edges between a pair of nodes and self-loops.
- Confused about how to submit your marathon match solution? This forum discusses how to submit your solution and how to alter your solution.

Hope you enjoy these awesome forums. Be sure to contribute and receive feedback from other members.

**maxwells_daemon**

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