Java uses adjacency matrix to achieve breadth first

To define a node class:

//一个节点class Vertex{    char label;    boolean wasVisited;    publicVertex(char label){        this.label = label;        false;     }}

Figure:

Class graph{Private Final intMax_verts = -;PrivateVertex vertexlist[];//Node list    Private intAdjmat[][];//adjacency matrix    Private intNverts;//Number of nodes    PrivateQueue Thequeue;//Assistance Queue     Public Graph() {vertexlist =NewVertex[max_verts]; Adjmat =New int[Max_verts]        [Max_verts]; Nverts =0; for(inti =0; i < max_verts; i++) { for(intj =0; J < Max_verts; J + +) Adjmat[i][j] =0; } Thequeue =NewArraydeque (); } Public void Addvertex(CharLab) {vertexlist[nverts++] =NewVertex (Lab); } Public void Addedge(intStartintEnd) {Adjmat[start][end] =1; Adjmat[end][start] =1; } Public void Displayvertex(intV) {System.out.print (Vertexlist[v].label); }//Gets the unreachable node that is adjacent to the V node     Public int Getadjunvisiedvertex(intV) { for(inti =0; i < nverts; i++) {if(Adjmat[v][i] = =1&& vertexlist[i].wasvisited = =false){returnI }        }return-1; }//Breadth-First search    /** * Rule 1: Access next neighbor of future access (if present), this vertex must be the adjacency point of the current vertex, marked as visited, and inserted into the queue * * Rule 2: If you cannot execute rule 1 because no vertices have been accessed, the queue The header takes a vertex (if present) and makes it * called the current vertex * Rule 3: If rule 2 cannot be executed because the queue is empty, the search ends */     Public void BFS() {vertexlist[0].wasvisited =true; Displayvertex (0);; Thequeue.offer (0);intv2; while(!thequeue.isempty ()) {intV1 = (int) Thequeue.remove (); while((v2 = Getadjunvisiedvertex (v1))! =-1) {vertexlist[v2].wasvisited =true;                Displayvertex (v2);            Thequeue.offer (v2); }        } for(inti =0; i < nverts; i++) {vertexlist[i].wasvisited =false; }    }   }

Test:

Graph thegraph = new graph ();Thegraph. Addvertex(' A ');Thegraph. Addvertex(' B ');Thegraph. Addvertex(' C ');Thegraph. Addvertex(' D ');Thegraph. Addvertex(' E ');Thegraph. Addvertex(' F ');Thegraph. Addvertex(' G ');Thegraph. Addvertex(' H ');Thegraph. Addvertex(' I ');Thegraph. Addedge(0,1);//abThegraph. Addedge(0,2);//acThegraph. Addedge(0,3);//adThegraph. Addedge(0,4);//aeThegraph. Addedge(1,5);//BFThegraph. Addedge(5,6);//FGThegraph. Addedge(3,6);//DGThegraph. Addedge(6,7);//giThegraph. BFS();

Breadth First search: ABCDEFGH

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Java uses adjacency matrix to achieve breadth first