Graph Interface

addNode()
@param: N name | the node label1
@returns: true if the node was added, otherwise false
public boolean addNode(N name);

addEdge()
@param: N to | the label of the node the edge is going to
@param: N from | the label of the node the edge is coming from
@param: E label | the label of the edge
@returns: true if the edge was added, otherwise false
public boolean addEdge(N to, N from, E label);

edgeCount()
@returns: an int representing the number of nodes in the graph
public int size();
@returns: an int representing the number of edges in the graph
public int edgeCount();

contains()
@param: N node_label | label of the node to check for in the graph
@returns: true if a node with the given label is in the graph, otherwise false
public boolean contains(N node_label);

getNodes()
@returns: A HashSet of the node labels of all nodes in the graph
public HashSet<N> getNodes();

getEdges()
@returns: A HashMap of the edge labels of all edges in the graph and the number of times that entry appears
public HashMap<E,Integer> getEdges();

getNeighborsTo()
@returns: A HashSet containing the labels of nodes you can get to from the given node. Returns an empty set if > the given node has no neighbors or is not in the graph.
public HashSet<N> getNeighborsTo(N node_label);

getNeighborsFrom()
@returns: A HashSet containing the labels of nodes you can get to the given node from. Returns an empty set if > the given node has no neighbors or is not in the graph.
public HashSet<N> getNeighborsFrom(N node_label);

shortestPath()
@param: source | the node label of the starting node
@param: destination| the node label of the destination node @returns: an ArrayList of node labels in order
from the source to the destination, empty ArrayList if the source node or destination node are not in the
graph. public ArrayList<N> shortestPath(N source, N destination);