One year. According to the relevant information of the query, the undergraduate discrete mathematics should be studied for at least one year, including at least: mathematical logic (propositional logic and predicate logic), set theory (set, relation, mapping, cardinality, countable set and uncountable set, etc. ), algebra (the concepts and basic properties of group ring field, lattice and Boolean algebra), graph theory (there are many choices about what to talk about, which can be difficult or easy). Discrete mathematics is a subject that combines many branches of mathematics related to computer science, mainly for undergraduate study of computer science and information science. People who study discrete mathematics often do research in one of them, such as combinatorial mathematics, graph theory, mathematical logic, computational complexity theory and so on.