Question

Create the code for GraphAlgorithm.prim() so that the MST main routine can run properly

public class MSTmain {

        public static void main(String[] args) {
                MyGraph G = new MyGraph(6);
                G.insertEdge(0, 2, 5);
                G.insertEdge(2, 0, 5);
                G.insertEdge(1, 0, 1);
                G.insertEdge(0, 1, 1);
                G.insertEdge(0, 5, 8);
                G.insertEdge(5, 0, 8);
                G.insertEdge(1, 2, 7);
                G.insertEdge(2, 1, 7);
                G.insertEdge(1, 3, 5);
                G.insertEdge(3, 1, 5);
                G.insertEdge(2, 3, 1);
                G.insertEdge(3, 2, 1);
                G.insertEdge(1, 5, 9);
                G.insertEdge(5, 1, 9);
                G.insertEdge(3, 4, 3);
                G.insertEdge(4, 3, 3);
                G.insertEdge(4, 2, 7);
                G.insertEdge(2, 4, 7);
                G.insertEdge(5, 2, 3);
                G.insertEdge(2, 5, 3);
                G.insertEdge(4, 5, 1);
                G.insertEdge(5, 4, 1);
                
                GraphAlgorithm.displayGraph(G);
                System.out.println();
                MyGraph H = GraphAlgorithm.prim(G);
                GraphAlgorithm.displayGraph(H);
                System.out.println(GraphAlgorithm.totalCost(H));
                System.out.println();
                MyGraph I = GraphAlgorithm.dijkstra(G,0,4);
                GraphAlgorithm.displayGraph(I);
                System.out.println(GraphAlgorithm.totalCost(I));
                System.out.println();
                
                

        }

}

----------------------------------------------------

public class GraphAlgorithm {
        
        public static double totalCost(MyGraph G) {
                double total = 0;
                Edge loc = G.first();
                while (!G.eol()) {
                        total = total + loc.cost;
                        loc = G.next();
                }
                return total;
        }
        
        public static void displayGraph(MyGraph G) {
                Edge loc = G.first();
                while (!G.eol()) {
                        System.out.println(loc.orig +" "+loc.dest+" "+loc.cost);
                        loc= G.next();
                }
        }
        
        public static MyGraph prim(MyGraph G) {
                INSERT CODE HERE
        }

        public static MyGraph cycle(MyGraph G, int source) {
                INSERT CODE HERE
        }
        
        public static MyGraph dijkstra(MyGraph G, int source, int terminal) {
                int n = G.getSize();
                MyGraph result = new MyGraph(n);
                double [] label = new double[n];
                label[source] = 0;
                int[] pred = new int[n];
                pred[source] = source;
                for (int i=0; i= 0 && pred[e.dest]  < 0 && label[e.orig] + e.cost < min) {
                                        best = e;
                                        min = label[e.orig] + e.cost;
                                }
                                e = G.next();
                        }
                        pred[best.dest] = best.orig;
                        label[best.dest] = label[best.orig] + best.cost;
                }
                int node = terminal;
                while (node != pred[node]) {
                        result.insertEdge(pred[node], node, G.getCost(pred[node],node));
                        node = pred[node];
                }
                return result;
        }
}
---------------------------------

public class Edge {
        public Edge(int i, int j, double c) {
                orig = i;
                dest = j;
                cost = c;
        }

        public int orig;
        public int dest;
        public double cost;
        public Edge next = null;
}

--------------------------------------------------------

public class MyGraph {
        public static final int MAXSIZE = 100;
        public static final double BIGM = 10000000;
        
        public MyGraph(int size) {
                n = size;
                nodeStart = new Edge[MAXSIZE];
                for (int i=0; i

Answer 1

public static MyGraph prim(MyGraph G) {

int n= G.getSize();

MyGraph re=new MyGraph(n);

boolean[] in=new boolean[n];

in[0]=true;

for(int i=1; i

{

in[i]=false;

}

for(int step=1;step

{

Edge best = null;

double min=MyGraph.BIGM;

Edge e= G.first();

while(!G.eol()) {

if(in[e.orig]&& !in[e.dest]&& e.cost

{

best=e;

min=e.cost;

}

e=G.next();

}

re.insertEdge(best.orig,best.dest, best.cost);

re.next();

in[best.dest]=true;

}

return re;

}