Dijkstra implementation in java

 package javaCodes;

import java.util.ArrayList;

import java.util.Scanner;

class dijkstra

{

private int vertices = 9;

void shortest_path(int g[][], int source)

{

int dis[] = new int[vertices];

boolean sptset[] = new boolean[vertices];

ArrayList<ArrayList<Integer>> path = new ArrayList<ArrayList<Integer>> (vertices);

for(int i=0; i < vertices; i++)

{

dis[i] = Integer.MAX_VALUE;

sptset[i] = false;

path.add(new ArrayList<Integer> ());

}

dis[source] = 0;

for(int v=0; v<vertices; v++)

{

int u = mindistance(dis, sptset);

sptset[u] = true;

for(int i=0; i<vertices; i++)

{

if(!sptset[i] && dis[u]!= Integer.MAX_VALUE && g[u][i]!=0 && dis[u] + g[u][i] < dis[i])

{

if(dis[i] == Integer.MAX_VALUE)

{

dis[i] = dis[u] + g[u][i];

for(int k=0; k < path.get(u).size(); k++)

{

path.get(i).add(path.get(u).get(k));

}

path.get(i).add(u);

}

else

{

dis[i] = dis[u] + g[u][i];

path.get(i).clear();

for(int k=0; k < path.get(u).size(); k++)

{

path.get(i).add(path.get(u).get(k));

}

path.get(i).add(u);

}

}

}

}

display(dis, path);

}

int mindistance(int[] dis, boolean[] sptset) {

int min = Integer.MAX_VALUE, min_index = -1;

for(int i=0; i<vertices; i++)

{

if(!sptset[i] && dis[i] < min)

{

min = dis[i];

min_index = i;

}

}

return min_index;

}

void display(int[] dis, ArrayList<ArrayList<Integer>> path) {

System.out.println("Distance of every node from source is : ");

for(int i=0; i < vertices; i++)

{

System.out.println("Node : "+ i +"   "+"Distance : "+dis[i]+"   ");

System.out.print("Shortest distance path is : ");

for(int j=0; j<path.get(i).size(); j++)

{

System.out.print(path.get(i).get(j)+"   ");

}

System.out.println("\n");

}

}

}

public class Dijkstra_algorithm {

public static void main(String args[])

{

int arr[][] = new int[9][9];

for(int i=0; i<=8; i++)

{

for(int j=0; j<=8; j++)

{

arr[i][j] = 0;

}

}

int edges;

Scanner sc = new Scanner(System.in);

System.out.print("Enter no of edges : ");

edges = sc.nextInt();

for(int i=0; i<edges; i++)

{

System.out.print("Now Enter left, right vertex and edge weight: ");

int temp1, temp2, temp3;

temp1 = sc.nextInt();

temp2 = sc.nextInt();

temp3 = sc.nextInt();

arr[temp1][temp2] = temp3;

arr[temp2][temp1] = temp3;

}

dijkstra obj = new dijkstra();

obj.shortest_path(arr, 0);

}

}