I need to implement these methods using an Adjacency Matrix. I am struggling with the removeNode method. Removing a node at the end of the matrix is simple, but if I need to remove a node somewhere in the middle, then all of my index's get screwed up. This is the code I am using so far:

interface Graph boolean addNode (T x) Adds x to the set of nodes for this graph Returns true if and only if the node set changes as a result of this call boolean addEdge(T x, T y); Adds the edge (x,y) to this graph. If either x or y are new nodes, they are also added to the node set. Returns true if and only if the edges set changes as result of this call Set> removeNode (T x) Removes x from the graph, as well as all edges for which x is either a source or target Returns the set of edges that was renoved ed. boolean remove Edge (T x, T y); Removes the edg (x,y) from this graph, as well as the e (y,x), if the dge graph is undirected. Neither of the nodes x or y are removed. Returns true if the graph changes as a result of this call