For questions about discrete optimization, which is a branch of optimization with discrete variables, opposed to continuous optimization in applied mathematics and computer science.
Discrete optimization is a branch of optimization in applied mathematics and computer science. As opposed to continuous optimization, some or all of the variables used in a discrete mathematical program are restricted to be discrete variables — that is, to assume only a discrete set of values, such as integers.
Two notable branches of discrete optimization are: combinatorial optimization, which refers to problems on graphs, matroids and other discrete structures, and integer programming.
These branches are closely intertwined however since many combinatorial optimization problems can be modeled as integer programs (e.g. shortest path) and conversely, integer programs can often be given a combinatorial interpretation.