static void Main(string[] args) { SudokuWriter sudokuWriter = new SudokuWriter(); ImmutableSudokuGrid filledGrid = sudokuWriter.CreateFilledGrid(); filledGrid.PrintGrid(); Console.WriteLine("\n"); ImmutableSudokuGrid emptiedGrid = sudokuWriter.EmptyGridForHardSolve(filledGrid); emptiedGrid.PrintGrid(); Console.WriteLine("\n"); SudokuGrid mutableEmptiedGrid = emptiedGrid.MakeMutableCopy(); SudokuSolver sudokuSolver = new SudokuSolver(); sudokuSolver.Solve(mutableEmptiedGrid); mutableEmptiedGrid.PrintGrid(); if (mutableEmptiedGrid.FindAllEmptySquares().Count != 0) { Console.WriteLine("\n"); HarderSudokuSolver harderSolver = new HarderSudokuSolver(); ImmutableSudokuGrid solvedGrid = harderSolver.Solve(emptiedGrid); solvedGrid.PrintGrid(); } }