Graph TheoryIt is a branch of combinatorial mathematics, and its main research object is graph. Here, graph refers to a figure composed of several given vertices and edges connecting two vertices. It is often used to describe special relationships between things, where vertices represent things and edges represent the connections between them.

Graph theory originated from the problem of the seven bridges of Königsberg, which was solved by Euler in 1736, so he is considered the founder of graph theory.

References

【1】Graph theory - Wikipedia