Method AddEdge

data-structures/graph/graph.go:107–135

(from, to VertexId, weight int)

}

func (g *graph) AddEdge(from, to VertexId, weight int) error {
	if from == to {
		return errors.New("Cannot add self loop")
	}

	if !g.CheckVertex(from) || !g.CheckVertex(to) {
		return errors.New("Vertices don't exist")
	}

	i, _ := g.edges[from][to]
	j, _ := g.edges[to][from]

	if i > 0 || j > 0 {
		return errors.New("Edge already defined")
	}

	g.TouchVertex(from)
	g.TouchVertex(to)

	g.edges[from][to] = weight

	if !g.isDirected {
		g.edges[to][from] = weight
	}

	g.edgesCount++

	return nil
}

func (g *graph) RemoveEdge(from, to VertexId) error {
	i, _ := g.edges[from][to]