Question

I need a java code to choose the shortest path through nodes using hill climbing algorithm.

Answer 1

package function;
import java.util.Scanner;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Stack;

class Ext
{
String source;
String destination;
int distance;
boolean skip;
Ext(String f, String t, int d)
{
    source = f;
    destination = t;
    distance = d;
    skip = false;
}
}

public class Extra
{
final int MAX = 100;
Ext flights[] = new Ext[MAX];
int numFlights = 0;
Stack btStack = new Stack();
public static void main(String args[])
{
    String destination, source;
    Extra ob = new Extra();
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    ob.setup();
    try
    {
      System.out.print("Source? ");
      source = br.readLine();
      System.out.print("Destination? ");
      destination = br.readLine();
      ob.isflight(source, destination);
      if (ob.btStack.size() != 0)
        ob.route(destination);
    }
    catch (IOException exc)
    {
      System.out.println("Error on input.");
    }
}

// Initialize the flight database.
void setup()
{
    addFlight("New York", "Chicago", 900);
    addFlight("Chicago", "Denver", 1000);
    addFlight("New York", "Torondestination", 500);
    addFlight("New York", "Denver", 1800);
    addFlight("Torondestination", "Calgary", 1700);
    addFlight("Torondestination", "Los Angeles", 2500);
    addFlight("Torondestination", "Chicago", 500);
    addFlight("Denver", "Urbana", 1000);
    addFlight("Denver", "Housdestinationn", 1000);
    addFlight("Housdestinationn", "Los Angeles", 1500);
    addFlight("Denver", "Los Angeles", 1000);
}

void addFlight(String source, String destination, int dist)
{
    if (numFlights < MAX)
    {
      flights[numFlights] = new Ext(source, destination, dist);
      numFlights++;
    }
    else
      System.out.println("Flight database full.\n");
}

void route(String destination)
{
    Stack rev = new Stack();
    int dist = 0;
    Ext f;
    int num = btStack.size();
    for (int i = 0; i < num; i++)
      rev.push(btStack.pop());
    for (int i = 0; i < num; i++)
    {
      f = (Ext) rev.pop();
      System.out.print(f.source + " destination ");
      dist += f.distance;
    }

    System.out.println(destination);
    System.out.println("Distance is " + dist);
}

int match(String source, String destination)
{
    for (int i = numFlights - 1; i > -1; i--)
    {
      if (flights[i].source.equals(source) && flights[i].destination.equals(destination)&& !flights[i].skip)
      {
        flights[i].skip = true;
        return flights[i].distance;
      }
    }
    return 0;
}

Ext find(String source)
{
    int pos = -1;
    int dist = 0;
    for (int i = 0; i < numFlights; i++)
    {
      if (flights[i].source.equals(source) && !flights[i].skip)
      {
        if (flights[i].distance > dist)
        {
          pos = i;
          dist = flights[i].distance;
        }
      }
    }

    if (pos != -1)
    {
      flights[pos].skip = true;
      Ext f = new Ext(flights[pos].source, flights[pos].destination,flights[pos].distance);
      return f;
    }

    return null;
}

void isflight(String source, String destination)
{
    int dist;
    Ext f = null;
    dist = match(source, destination);
    if (dist != 0)
    {
      btStack.push(new Ext(source, destination, dist));
      return;
    }
    if (f != null)
    {
      btStack.push(new Ext(source, destination, f.distance));
      isflight(f.destination, destination);
    }
    else if (btStack.size() > 0)
    {
      f = (Ext) btStack.pop();
      isflight(f.source, f.destination);
    }
}
}