inDegree method

int? inDegree(
  1. T vertex
)
inherited

Returns the number of incoming directed edges for vertex.

Returns null if vertex is not a graph vertex.

Implementation

int? inDegree(T vertex) {
  if (!vertexExists(vertex)) {
    return null;
  }
  var inDegree = 0;
  for (final start in vertices) {
    if (edgeExists(start, vertex)) {
      ++inDegree;
    }
  }
  return inDegree;
}