//Implementation of Optimization Techniques - Part 1

//Program name: H2

​

using System;

using System.Collections.Generic;

​

class H2

{

    static void Main(string[] args)

    {

        //input max value and number of values

        Console.Write("Enter the maximum number for lotto: ");

        int max_number = Convert.ToInt32(Console.ReadLine());

        Console.Write("Enter the number of values to be generated: ");

        int num_values = Convert.ToInt32(Console.ReadLine());

        //generate random number

        Random random = new Random();

        //apply generate_drawing and num_tips

        List<int> drawing = generate_drawing(random, max_number, num_values);

        long number_of_tips = num_tips(max_number, num_values);

        Console.Write("Lotto numbers: ");

        foreach (int number in drawing)

        {

            Console.Write(number + " ");

        }

​

        Console.WriteLine($"| {number_of_tips} possible tips");

        //print out 10 tips and their matches

        for (int i = 1; i <= 10; i++)

        {

            List<int> tip = generate_drawing(random, max_number, num_values);

            int matches = match_count(drawing, tip);

            Console.WriteLine($"Tip {i}: {string.Join(" ", tip)} | {matches} numbers match");

        }

    }

​

    // define function generate_drawing

    static List<int> generate_drawing(Random random, int max_number, int num_values)

    {

        List<int> drawing = new List<int>();

        while (drawing.Count < num_values) //limit the number of time to generate the values

        {

            int number = random.Next(1, max_number + 1);

            if (!drawing.Contains(number)) //check to make sure there is no duplicate when chooing number

            {

                drawing.Add(number); //add new number to the drawing

            }

        }

​

        drawing.Sort(); //sort the list to make it easier to look at

        return drawing;

    }

​

    // define function num_tips

    static long num_tips(int max_number, int num_values)

    {

        long num_tips = 1;

        //using the definition of combination n!/k!(n-k)! (wikipedia) where n is max_number, k is num_values

        //we can eliminate the product from (n-k) to 1. Only (n-k+1) to n left.

        //1 st loop: calculate n!/(n-k)!

        for (int i = max_number; i > max_number - num_values; i--)

        // value of i from max_number (n) to max_number - num_values (n-k), take the greater int -> (n-k+1)

        {

            num_tips *= i; //multiply over each iteration

        }

​

        //2nd loop: calculate k! 

        for (int i = 2; i <= num_values; i++)

        {

            num_tips /= i;

        }

​

        return num_tips;

    }

​

    static int match_count(List<int> drawing, List<int> tip)

    {

        int matches = 0;

        foreach (int number in tip)

        {

            if (drawing.Contains(number)) //check if there is any number in each tip matched the drawing list

            {

                matches++;

            }

        }

​

        return matches;

    }

}