Directed graph
（重定向自Outdegree）
![A directed graph.](/Images/godic/202501/31/Directed.svg5351.png")
![Directed graph with corresponding incidence matrix.](/Images/godic/202501/31/Incidence_matrix_-_directed_graph.svg5351.png")
![A directed graph with vertices labeled (indegree, outdegree).](/Images/godic/202501/31/DirectedDegrees.svg5351.png")
![A tournament on 4 vertices.](/Images/godic/202501/31/4-tournament.svg5351.png")
In mathematics, and more specifically in graph theory, a directed graph (or digraph) is a graph, or set of vertices connected by edges, where the edges have a direction associated with them. In formal terms, a directed graph is an ordered pair G = (V, A) (sometimes G = (V, E)) where