The paper discusses a certain type of competitions based on distance interaction of a participant with simulation models of concepts from discrete mathematics and computer science. One of them is the “Construct, Test, Explore” (CTE) competition, developed by the authors, the other is the Olympiad in Discrete Mathematics and Theoretical Informatics (DM&TI). The tasks presented in this paper are generally devoted to the concept of a graph isomorphism. Most of the tasks are verified automatically.
A reversible sequence of steps from the specification of the algorithm and the mathematical definition of the recurrent solution through the recursive procedure, the tail recursive procedure and finally to the iteration procedure, is shown. The notation for analysing recursive function execution as well as modified flow charts of an algorithm to identify the differences between the iteration and the tail recursion are proposed. All the procedures are written in Logo, so the lists are used as the data structure. Transformation from the recursive procedure to the iterative procedure and vice versa can be shown in such a way in every language in which the recursion is allowed. All examples are one-recursion-call examples and all except one are the functions of discrete mathematics.