Clique in an undirected graph is a subgraph that is complete. Particularly, if there is a subset of k vertices that are connected to each other, we say that graph contains a k-clique.

The task is to detect and repair a singly linked list that contains cycle. And the solution is fast, very simple and brilliant.

Here’s an idea. Iterate through the list using two pointers — slow and fast. Slow pointer iterates node by node…

Zig-zag scan of a matrix is useful when you transform your 2D data between domains and the transformation tends to accumulate information into top left corner.

An example is JPEG image compression with discrete cosine transform, which accumulates energy to the left [in 1D]…

Gram-Schmidt orthogonalization is a method used in linear algebra to produce an orthogonal [or orthonormal] base that generates the same vector space as a linear span of a given set of vectors.

Bloom filter is a probabilistic data structure based on hashing. It’s very similar to hash table, but differs in several important aspects.

• only add() and contains() operations are supported (I’ll skip union)
• contains() may return false…

Anytime data is transferred or stored, there are errors occurring which leads to data corruption. Computer memory, disk, ethernet, wi-fi, … it happens everywhere. Hamming code was an impressive discovery of how to deal with the problem efficiently.