How to creare ArrayList and skip it through the loop

Question

I want to write a card exchange game. I have an Arraylist of Colors in which values start from -1 to 6. Each element of this array implies id colors. There is also an ArrayList Player Properties in which cards with colors are stored. I need to create an ArrayList with eight zeros that will imply id Colors. Next, skip the ArrayList Player Properties through this array and if there is some element in the array, then increase the ArrayList Colors index by +1.

Eg:

ArrayList Colors =new ArrayList(){-1,0,1,2,3,4,5,6};
ArrayList Player Properties = new ArrayList(){0,4,6};
This array should imply that its element is an element of the Colors array
ArrayList buffer = new ArrayList(){0,0,0,0,0,0,0,0};
If an array comes to the input in this form: {0,4,6};
Then the index of this array is added by +1, like this: {0,1,0,0,0,1,0,1}; 

How do I implement this in code?

I don't have any code examples because I don't know how to implement it, sorry in advance that I didn't provide more code, I really need help, thank you all in advance for your help

Answer 1

What you want is a histogram of the card values that you accumulate.

Since this is C# you better start thinking of a data model for each player. There are two arrays to consider, one with the card values: -1,0,..6 and one with the card counts, how many of each card a player has.

Here is how this would play out:

static class Program
{
    static void Main(string[] args)
    {
        var player1 = new Player("Player1");

        Console.WriteLine(player1);            
        // Player1 : 0,0,0,0,0,0,0,0

        player1.Hand(0,4,6);
        Console.WriteLine(player1);
        // Player1: 0,1,0,0,0,1,0,1
    }
}

You can to this point with the following Player class that handles the logic inside the .Hand() method.

public class Player
{
    public static readonly int[] CardValues = { -1, 0, 1, 2, 3, 4, 5, 6 };
    public Player(string name)
    {
        CardCounts = new int[CardValues.Length];
        Name = name;
    }
    public int[] CardCounts { get; }
    public string Name { get; }
    public void Hand(params int[] cards)
    {
        foreach (var card in cards)
        {
            int index = Array.IndexOf(CardValues, card);
            if (index >= 0)
            {
                CardCounts[index] += 1;
            }
        }
    }
    public override string ToString()
    {
        return $"{Name} : {string.Join(",", CardCounts)}";
    }
}

---

Note that ArrayList is really old technology, and not type safe. In it place there is List<>, but in this case the length of the array is fixed since there is a finite set of card values, and that does not change, so no need for a collection, as a plain old Array would suffice.

Answer 2

Because your array is a fixed representation:

var Colors = new []{-1,0,1,2,3,4,5,6};
var PlayerProperties = new []{0,4,6};
var buffer = new []{0,0,0,0,0,0,0,0};

You can calculate which indexes in the buffer should be set to 1

foreach(var pp in PlayerProperties)
  buffer[pp+1] += 1;

Value 0 always occurs at index 1. Value 4 always occurs at index 5. Value 6 always occurs at index 7. Thus the formula is value+1..

Answer 3

You can use the Linq function Contains to check if a value is present in an array. Something like this:

    var colors = new int[] { -1, 0, 1, 2, 3, 4, 5, 6 };
    var playerProperties = new int[] { 0, 4, 4, 6 };
    var result = colors.Select(c => playerProperties.Where(x => x == c).Count());
    Console.WriteLine(string.Join(", ", result));

prints 0, 1, 0, 0, 0, 2, 0, 1