The book contains the necessary information from the theory of algorithms, graph theory, combinatorics. Partially recursive functions, Turing machines are considered, some variants of algorithms are given (associative calculus, substitution systems, grammar, Post products, normal Markov algorithms, operator algorithms). The main types of graphs are described (multigraphs, pseudographs, Euler graphs, Hamiltonian graphs, trees, bipartite graphs, matchings, Petri nets, planar graphs, transport networks). Some commonly used graph algorithms are given. Classical combinatorial configurations and their generating functions, recurrent sequences are considered.