NearestNeighbour.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Travelling_SalesMan_Problem
{
    class NearestNeighbour
        
    {
        public ShortestPath display;
        public NearestNeighbour(ShortestPath display)
        {
            this.display = display;
        }
        public Route FindShortestRoute(ArrayList cities)//calculate the total distance 
        {
            ArrayList ShortestRouteCities = new ArrayList();
            City city = new City("Bahria University", 24.893277, 67.08818145);// cities will be picked from here

            updatesRoutes(ShortestRouteCities, cities, city);
            while (cities.Count >= 1)
            {
                city = getNextCity(cities, city);
                updatesRoutes(ShortestRouteCities, cities, city);
            }
            printShortestRout(ShortestRouteCities);
            return new Route(ShortestRouteCities);
        }
        private void printShortestRout(ArrayList shortestRouteCities)
        {
            this.display.output.Text = null;
            foreach (City city in shortestRouteCities)// iterrate on cities to print next name of city
            {
                this.display.output.Text = this.display.output.Text + city.getName() + "\n";
            }
            this.display.output.Text = this.display.output.Text + "Bahria University" + "\n";
        }
        private void updatesRoutes(ArrayList shortestRouteCities, ArrayList cities, City city)//we update the list after picking any city from the list
        {
            shortestRouteCities.Add(city);
            cities.Remove(city);
        }

        private City getNextCity(ArrayList cities, City city) // find the minimum distance from list of cities and pick the city with minimum distance.
        {
            int min_index = 0;
            double minDistance = city.measureDistance((City)cities[0]);
            for (int row = 0; row < cities.Count - 1; row++)
            {
                double minDistanceNext = city.measureDistance((City)cities[row + 1]);

                if (minDistanceNext == 0)
                    continue;
                if (minDistance == 0 || minDistanceNext < minDistance)
                {
                    min_index = row + 1;
                    minDistance = minDistanceNext;
                }
            }
            return (City)cities[min_index];
        }
    }
}