Create Dijkstra_shortest_path.java

Dynamic Programming/Dijkstra_shortest_path.java

@@ -0,0 +1,87 @@
+import java.util.Scanner;
+
+public class Dijkstra
+{
+	static Scanner scan; 
+
+	public static void main(String[] args)
+	{
+		int[] preD = new int[5];
+		int min = 999, nextNode = 0; 
+		scan = new Scanner(System.in);
+		int[] distance = new int[5]; 
+		int[][] matrix = new int[5][5]; 
+		int[] visited = new int[5]; 
+
+		System.out.println("Enter the cost matrix");
+
+		for (int i = 0; i < distance.length; i++)
+		{
+			visited[i] = 0; 
+			preD[i] = 0;
+
+			for (int j = 0; j < distance.length; j++)
+			{
+				matrix[i][j] = scan.nextInt(); //fill the matrix
+				if (matrix[i][j]==0)
+					matrix[i][j] = 999; // make the zeros as 999
+			}
+		}
+
+		distance = matrix[0]; 
+		visited[0] = 1; 
+		distance[0] = 0; 
+
+		for (int counter = 0; counter < 5; counter++)
+		{
+			min = 999;
+			for (int i = 0; i < 5; i++)
+			{
+				if (min > distance[i] && visited[i]!=1)
+				{
+					min = distance[i];
+					nextNode = i;
+				}
+			}
+
+			visited[nextNode] = 1;
+			for (int i = 0; i < 5; i++)
+			{
+				if (visited[i]!=1)
+				{
+					if (min+matrix[nextNode][i] < distance[i])
+					{
+						distance[i] = min+matrix[nextNode][i];
+						preD[i] = nextNode;
+					}
+
+				}
+
+			}
+
+		}
+
+		for(int i = 0; i < 5; i++)
+			System.out.print("|" + distance[i]);
+
+		System.out.println("|");
+
+		int j;
+		for (int i = 0; i < 5; i++)
+		{
+			if (i!=0)
+			{
+
+				System.out.print("Path = " + i);
+				j = i;
+				do
+				{
+					j = preD[j];
+					System.out.print(" <- " + j);
+				}
+				while(j != 0);
+			}
+			System.out.println();
+		}
+	}
+}