DEV Community

David Berry
David Berry

Posted on

Generating Lottery Numbers

I started buying lottery tickets when Powerball was nearing a payout of $2B. I bought five quick picks (machine generated numbers) and noticed that there were many duplicated numbers across the five picks. I even had two picks that started with the same two numbers. After the drawing, I found that I had zero matching numbers and decided that there must be a better way to generate the numbers and at least get more matching numbers.

OBVIOUS DISCLAIMERS:

  • There is nothing here that changes the odds of winning.
    • Powerball is 1 in 292,201,338
    • MegaMillions is 1 in 302,575,350.
  • All random number generators are not really random.
  • This algorithm just generates picks with non-repeating numbers.
  • This algorithm does make me feel better because I can circle more matching numbers

TERMINOLOGY
The Mega Millions description of how to play defines each pick as a "board", and each "board" consists of two pools of number. Pool 1 consists of 5 non-repeating numbers from 1 to 70. Pool 2 is 1 number from 1 to 25.

REQUIREMENTS

  • The program should support multiple lotteries
  • The arguments should be pool definitions in the form of "selections:max_num".
    • Powerball = "5:69 1:26"
    • Mega Millions = "5:70 1:25"
  • The program should figure out the minimum number of boards required to include all the numbers.

CLASSES
Lotto is responsible for parsing the command-line arguments, creating the pools, and printing out each board. The main loop is as follows:

      if (args.Length < 2)
        throw new ArgumentException("Wrong Number of Arguments");

      var pools = ParsePools(args);
      var minBoards = GetMinBoards(pools);
      var board = new List<ushort>();
      for (int i = 0; i < minBoards; i++)
      {
        foreach (var pool in pools)
        {
          pool.MoveNext();
          board.AddRange(pool.Current);
        }
        PrintBoard(i+1, board);
        board.Clear();
      }
Enter fullscreen mode Exit fullscreen mode

ParsePools(args) parses the command-line arguments and returns a List<Pool>. GetMinBoards(pools) gets the minimum number of boards for each pool and returns the greatest. Next it iterates minBoards times and gets the next pick for each pool and adds it to the board. You may have noticed that Pool is an IEnumerator. Pool implements the IEnumerator<List<ushort>> interface.

public class Pool : IEnumerator<List<ushort>>
{
  private static Random _random = new Random();
  private List<ushort> _available;
  public ushort Selections { get; }
  public ushort MaxNumber { get; }


  public Pool(ushort selections, ushort maxNumber)
  {
    Selections = selections;
    MaxNumber = maxNumber;
    _available = LoadAvailable(maxNumber);
    Current = new List<ushort>();
  }
}
Enter fullscreen mode Exit fullscreen mode

The Pool constructor takes as arguments, the number of selections that must be made for the pool and the maximum number that can be chosen. LoadAvailable adds integers 1..MaxNumber into a list for use in the board. Keeping the numbers in an available list allows the program not to have to remember the selections that were already made. A random number is generated as an index into the list and that item is used and removed. When the available list is empty, we call LoadAvailable again and immediately remove any numbers that are in the current unfinished board so that duplicates are avoided. When all the selections are made for the current pool, the selections are sorted.

  private void GetNextBoard()
  {
    Current.Clear();
    if (_available.Count < Selections)
    {
      Current.AddRange(_available);
      _available = LoadAvailable(MaxNumber, Current);
    }

    while (Current.Count < Selections)
    {
      int pick = _random.Next(0, _available.Count - 1);
      Current.Add(_available[pick]);
      _available.RemoveAt(pick);
      if (!_available.Any())
      {
        _available = LoadAvailable(MaxNumber, Current);
      }
    }

    Current.Sort();
  }
Enter fullscreen mode Exit fullscreen mode

The last thing to remember is to call ceiling when calculating the minimum number of boards so that you don't miss some numbers because of a rounding error.

  public ushort MinBoards()
  {
    double boards = Math.Ceiling((double)MaxNumber / Selections);
    return (ushort)boards;
  }
Enter fullscreen mode Exit fullscreen mode

Running the program for PowerBall is as follows:

lotto 5:69 1:26
Enter fullscreen mode Exit fullscreen mode

which returns

 1:  02 16 35 42 53 25
 2:  24 36 39 41 51 11
 3:  06 32 46 56 65 17
 4:  33 34 47 61 66 15
 5:  04 17 22 25 57 01
 6:  11 38 50 59 62 09
 7:  05 07 09 37 49 06
 8:  12 13 28 44 45 18
 9:  03 08 14 26 40 03
10:  19 31 52 63 68 20
11:  01 15 21 29 67 08
12:  10 43 48 54 64 19
13:  20 23 27 30 58 24
14:  18 51 55 60 69 21
15:  04 14 39 56 62 22
16:  26 27 49 53 57 23
17:  12 21 22 36 38 13
18:  01 02 25 31 46 12
19:  09 13 19 44 63 16
20:  03 20 23 33 48 14
21:  08 35 37 47 66 07
22:  05 17 29 45 50 04
23:  06 11 40 42 54 02
24:  41 52 58 65 67 05
25:  07 10 16 28 64 10
26:  15 24 30 59 61 26
Enter fullscreen mode Exit fullscreen mode

I hope you enjoyed this coding tangent I went on. If you happen to win the lottery using any numbers generated by lotto, I accept gratuities. The code is available here

Top comments (4)

Collapse
 
atmospherecw profile image
Anatollo • Edited

I've only played the lottery a couple of times in my life. I don't trust it at all. Only a completely lucky person can win. I study online casinos more at kaszinomagyar.com/ and everything connected with it. What you've sold is, of course, cool and unique. But it definitely doesn't suit me. I've already moved on from it.

Collapse
 
tomford profile image
tomford51 • Edited

It sounds like your experience with quick pick tickets during the massive Powerball draw was pretty frustrating. If you’re looking to improve your odds with a different approach to number selection, checking out alternative methods might be helpful. You could explore lttry.com/play/gg-world-x for an innovative way to generate lottery numbers. Sometimes, manual selection or using a lottery strategy can offer a different experience, potentially increasing the chances of getting some matching numbers.

Collapse
 
berryware profile image
David Berry

Thanks @tomford . How much have you won with that approach?

Collapse
 
fersadilala profile image
Lora

Well, it's a 50/50 chance.