The Graph object

mutable struct Graph{T}
    nodes::Set{T}
    edges::Dict{T, Set{T}}
end

Undirected graph where nodes are of type T.

• nodes::Set{T}: Holds the nodes of the graph.
• edges::Dict{T, Set{T}}: Holds the edges of the graph. For a given node as key, holds all the connected nodes as value of the Dict.

function Graph{T}()

Contructor of empty Graph.

function Graph{T}(nodes::Set{T}) where T
function Graph{T}(nodes::Vector{T}) where T

Constructor of Graph with a list of nodes and empty edges.

• nodes: Intial nodes.

function getnodes(graph::Graph{T}) where T = copy(graph.nodes)

Returns (shallow copy of) nodes in the Graph.

function hasnode(graph::Graph{T}, node::T) where T

Checks whether a node is in the Graph.

function addnode!(graph::Graph{T}, node::T) where T

Adds a node to the Graph.

function addedge!(graph::Graph{T}, node1::T, node2::T) where T

Adds an edge between node1 and node2. If node1 or node2 are not present in the Graph, they are added.

function isneighbor(graph::Graph{T}, node1::T, node2::T)::Bool where T

Checks whether node1 and node2 are connected by an edge.

function bfs(graph::Graph{T},
             source::T,
             destination::Union{Nothing, T} = nothing) where T

Performs a BFS starting from the node source (and optionally, to the destination).

Return values

• ::Dict{T, Int}: Distances of nodes (key) in the BFS path.
• ::Dict{T, T}: Parents of nodes (key) in the BFS path.

function nodes_from_bfs(graph::Graph{T}, source::T;
                        reverse::Bool = false) where T

function nodes_from_bfs(graph::Graph{T}, source::T,
                        destinations::Union{Set{T}, Vector{T}};
                        reverse::Bool = false) where T

Returns the Vector of nodes in the BFS path from the source (optionally, towards the destinations). If reverse=true returns the reverse order of nodes.

function shortest_path(graph::Graph{T}, source::T, destination::T) where T

Returns the shortest path between source and destination in a Graph.

function nextnode_in_path(graph::Graph{T}, source::T, destination::T, n=1) where T

Returns the next node in the shortest path between source and destination in a Graph. Optionally, finds nth next-node in the path.

function has_cycle(graph::Graph{T}) where T

Checks whether a Graph has cycles/loops in it.

function find_sum_central_node(graph::Graph{T}) where T
function find_sum_central_node(graph::Graph{T}, nodes::Set{T}) where T
function find_sum_central_node(graph::Graph{T}, nodes::Vector{T}) where T

Finds the sum central node node of a Graph. Optionally, when nodes is specified, finds the central node with respect to the nodes.

function find_eccentric_central_node(graph::Graph{T}) where T
function find_eccentric_central_node(graph::Graph{T}, nodes::Set{T}) where T
function find_eccentric_central_node(graph::Graph{T}, nodes::Vector{T}) where T

Finds the eccentric central node of a Graph. Optionally, when nodes is specified, finds the central node with respect to the nodes.

function Base.copy(graph::Graph{T}) where T

Shallow copy of Graph.

function Base.getindex(graph::Graph{T}, node::T) where T

Returns the edges for a given node::T as an index.

function Base.setindex!(graph::Graph{T}, neighbors::Set{T}, node::T) where T
function Base.setindex!(graph::Graph{T}, neighbors::Vector{T}, node::T) where T

Sets the edges=neighbors for a given node::T as an index.

function Base.:(==)(graph1::Graph{T}, graph2::Graph{T}) where T

Equality between two Graph objects.