Algorithm of transformation of a graph into another one with minimal cost

The authors study orgraphs with any number of chains and cycles. Edges of orgraphs have unique names — natural numbers. There is a fixed list of operations that transform one graph into another. A cost is assigned to each operation. The task is to find the path of transformations with minimal total cost. This problem has a wide range of practical applications. The task is probably NP-hard and, thus, can be solved only under constraints imposed on costs or graphs. Such solutions are proposed in the study. The corresponding algorithms are linear in time and memory and are proved to be exact (nonheuristic), i. e., to find the path of transformations with minimal cost. Many heuristic algorithms solving this problem are known and tested on various data, but the proposed solutions are the first exact solutions.