sudoku-solver/src/EndMove.Sudoku.Solver.Core/Algorithms/SolverBase.cs

namespace EndMove.Sudoku.Solver.Core.Algorithms;

public abstract class SolverBase : ISolver
{
    internal readonly Action<int[,]> DisplayBoard;

    /// <summary>
    /// Constructor for base solver algorithms
    /// </summary>
    /// <param name="displayBoard">Method to display board in terminal or other</param>
    protected SolverBase(Action<int[,]> displayBoard)
    {
        DisplayBoard = displayBoard;
    }

    public virtual bool IsValid(int[,] board, int row, int col, int n)
    {
        // Check Col, Row
        for (int i = 0; i < 9; i++)
        {
            if (board[row, i] == n || board[i, col] == n)
            {
                return false;
            }
        }
        // Check Box
        int xSize = col - (col % 3), ySize = row - (row % 3);
        for (int y = ySize; y < ySize + 3; y++)
        {
            for (int x = xSize; x < xSize + 3; x++)
            {
                if (board[y, x] == n)
                {
                    return false;
                }
            }
        }
        return true;
    }

    public virtual bool IsValid(int[] board, int row, int col, int n)
    {
        throw new NotImplementedException();
    }

    public abstract (bool, int[,]) Solve(int[,] board);
    public abstract (bool, int[]) Solve(int[] board);
}