Minimax.Connect4/Extensions.cs

using Connect4;

namespace MinMaxAB;

public static class Extensions
{
    public static Player[][] Fill(int cols, int rows, Player value)
    {
        Player[][] array = new Player[cols][];
        var arr = new Player[rows];
        for (int j = 0; j < rows; j++)
        {
            arr[j] = value;
        }
        array[0] = arr;
        for (int i = 1; i < cols; i++)
        {
            array[i] = new Player[rows];
            arr.CopyTo(array[i].AsSpan());
        }

        return array;
    }

    public static Player[][] DeepCopy(this Player[][] source)
    {
        var len = source.Length;
        var dest = new Player[len][];

        for (var i = 0; i < len; i++)
        {
            var inner = source[i];
            var ilen = inner.Length;
            var newer = new Player[ilen];
            Array.Copy(inner, newer, ilen);
            dest[i] = newer;
        }

        return dest;
    }
}