Basic Graph Data Structure Initialization Using Java Programming.

 Graph

                    (4) -------------(3)

                /                            \

             /                                 \

        (5)------------(1)-----------(2)

in This Above graph 4 connected to 3 and 5. Then 3 connected to 2 and 4 and so on. Graph are Used To Various Algorithms and Technology for example, Shortest Path Algorithm.

            1.Graph.
            2.bidirectional Graph.
            3.Weighted Graph.

Bidirectional Graph

            We Can Travel Both Side . Like Two Way Road.

S======>E   and E<=====S (start to end and end to start) vice versa.

Weighted Graph

            Weighted Graph Have Length Of Path. Like Km Is Roadways.

Properties

1. vertex
2. edge

Vertex is a defined as start or end point.

Edge is a connection between start and end points

   

import java.util.*;

class graph<T>{

HashMap<T,LinkedList<T>> g=new HashMap<T,LinkedList<T>>();

public void addVertex(T vertex){

g.put(vertex,new LinkedList<T>());

}

public void makeEdge(T start,T end,boolean byDirection){

//Check Start vertex Is Already Available Or Not

if(!g.containsKey(start)){

addVertex(start);

}

//Check Start vertex Is Already Available Or Not

if(!g.containsKey(end)){

addVertex(end);

}

//Add Root From Start To End

g.get(start).add(end);

//Add Root From Path End to Start

if(byDirection){

g.get(end).add(start);

}

}

public graph getGraph(){

return this;

}

}

class adjencencyList{

public static void main(String[] args){

graph<Integer> g=new graph<Integer>();

g.makeEdge(5,10,true);

g.makeEdge(5,15,true);

g.makeEdge(15,20,true);

System.out.println(g.getGraph().g);

}

}

output:

{20=[15], 5=[10, 15], 10=[5], 15=[5, 20]}