"discreet" is not spelled "discrete". "Discrete" is as in discrete math. "Discreet" is as in having sound judgement. Discreet : Discretion :: Discrete : Discreteness

some graph theory. Graphs can be easily represented by a matrix called a Laplacian matrix, which has the property whereby the dimension of the null space is the number of connected components in the graph.

a big french pig-in-a-blanket is called a "saucisson en croûte". (I've had one that had cheese inside, too. Mmmm)

Python implements heaps by manipulating lists through the heapq module. You can't pass a custom compare function to most of its functions, but you can use a list of tuples with (priority, ...) and the heapq functions will heap based off the first (and following, for tiebreakers) fields.

some SQL. WHERE clauses filter before aggregation functions; HAVING clauses filter after aggregation functions and GROUP BYs and can be used to implement filtering based on conditionals including aggregation functions.