Directed Graph - Indegree and Outdegree

Indegree and Outdegree

For a node, the number of head endpoints adjacent to a node is called the indegree of the node and the number of tail endpoints adjacent to a node is its outdegree (called "branching factor" in trees).

The indegree is denoted and the outdegree as A vertex with is called a source, as it is the origin of each of its incident edges. Similarly, a vertex with is called a sink.

The degree sum formula states that, for a directed graph,

If for every node v ∈ V, the graph is called a balanced digraph.