In JAVA Using the Data structure of your choice Diagraph AP

In JAVA:

Using the Data structure of your choice ( Diagraph API, Diagraph Search, Topological Sort, Kosaraju-Sharie, or Strong Components), write an application that will take a series of Check objects entered and sort them by check date implementing COMPARABLE. Also name the structure that was used.

Solution

package com.sanfoundry.graph;

import java.util.InputMismatchException;
import java.util.Scanner;
import java.util.Stack;

public class DigraphTopologicalSortingDFS
{
private Stack<Integer> stack;

public DigraphTopologicalSortingDFS()
{
stack = new Stack<Integer>();
}

public int[] topological(int adjacency_matrix[][], int source)
throws NullPointerException
{
int number_of_nodes = adjacency_matrix[source].length - 1;
int[] topological_sort = new int[number_of_nodes + 1];
int pos = 1;
int j;
int visited[] = new int[number_of_nodes + 1];
int element = source;
int i = source;
visited[source] = 1;
stack.push(source);
while (!stack.isEmpty())
{
element = stack.peek();
while (i <= number_of_nodes)
{
if (adjacency_matrix[element][i] == 1 && visited[i] == 1)
{
if (stack.contains(i))
{
System.out.println(\"TOPOLOGICAL SORT NOT POSSIBLE\");
return null;
}
}
if (adjacency_matrix[element][i] == 1 && visited[i] == 0)
{
stack.push(i);
visited[i] = 1;
element = i;
i = 1;
continue;
}
i++;
}
j = stack.pop();
topological_sort[pos++] = j;
i = ++j;
}
return topological_sort;
}

public static void main(String... arg)
{
int number_no_nodes, source;
Scanner scanner = null;
int topological_sort[] = null;
try
{
System.out.println(\"Enter the number of nodes in the graph\");
scanner = new Scanner(System.in);
number_no_nodes = scanner.nextInt();
int adjacency_matrix[][] = new int[number_no_nodes + 1][number_no_nodes + 1];
System.out.println(\"Enter the adjacency matrix\");
for (int i = 1; i <= number_no_nodes; i++)
for (int j = 1; j <= number_no_nodes; j++)
adjacency_matrix[i][j] = scanner.nextInt();
System.out.println(\"Enter the source for the graph\");
source = scanner.nextInt();
System.out
.println(\"The Topological sort for the graph is given by \");
DigraphTopologicalSortingDFS toposort = new DigraphTopologicalSortingDFS();
topological_sort = toposort.topological(adjacency_matrix, source);
for (int i = topological_sort.length - 1; i > 0; i--)
{
if (topological_sort[i] != 0)
System.out.print(topological_sort[i] + \"\\t\");
}
}
catch (InputMismatchException inputMismatch)
{
System.out.println(\"Wrong Input format\");
}
catch (NullPointerException nullPointer)
{
}
scanner.close();
}
}

Output: