public override bool SolveCell(Puzzle puzzle, int r, int c)
{
if (r == puzzle.TotalRows)
return true;
if (puzzle.Cells[r, c].Value != '-')
{
if (SolveNext(puzzle, r, c))
return true;
return false;
}
foreach (var nextValue in puzzle.CharacterSet)
{
if (IsValidMove(puzzle, r, c, nextValue))
{
puzzle.Cells[r, c].Value = nextValue;
if (SolveNext(puzzle, r, c))
return true;
}
}
puzzle.Cells[r, c].Value = '-';
return false;
}
public bool IsSolved(Puzzle puzzle)
{
for (int i = 0; i < puzzle.TotalRows; i++)
for (int j = 0; j < puzzle.TotalRows; j++)
if (puzzle.Cells[i, j].Value == '-')
return false;
return true;
}
public void CantSolve()
{
string[] solvedRows = "4231\n1342\n3124\n2413".Split();
Puzzle solvedPuzzle = new Puzzle(4, "1234", solvedRows);
bool solved = puzzle.Solve();
Assert.IsTrue(solved);
CollectionAssert.AreEqual(puzzle.Cells, solvedPuzzle.Cells);
}
public void ReadPuzzle9x9()
{
string[] expectedRows = "---------\n---------\n---------\n---------\n---------\n---------\n---------\n---------\n---------".Split();
Puzzle expected9 = new Puzzle(9, "123456789", expectedRows);
Puzzle actual9 = PuzzleReader.ReadPuzzle("test9.txt");
CollectionAssert.AreEqual(expected9.Cells, actual9.Cells);
CollectionAssert.AreEqual(expected9.CharacterSet, actual9.CharacterSet);
Assert.AreEqual(expected9.TotalRows, actual9.TotalRows);
}
public void ReadPuzzle4x4()
{
string[] expectedRows = "42-1\n---2\n3-2-\n-4-3".Split();
Puzzle expected4 = new Puzzle(4, "1234", expectedRows);
Puzzle actual4 = PuzzleReader.ReadPuzzle("test4.txt");
CollectionAssert.AreEqual(expected4.Cells, actual4.Cells);
CollectionAssert.AreEqual(expected4.CharacterSet, actual4.CharacterSet);
Assert.AreEqual(expected4.TotalRows, actual4.TotalRows);
}
private bool IsValidMove(Puzzle puzzle, int r, int c, char value)
{
var row = puzzle.RowAt(r);
var col = puzzle.ColumnAt(c);
var box = puzzle.BoxAt(r, c);
return !(row.Any(cell => cell.Value == value) ||
col.Any(cell => cell.Value == value) ||
box.Any(cell => cell.Value == value));
}
private bool SolveNext(Puzzle puzzle, int r, int c)
{
if (c == puzzle.TotalRows - 1)
{
if (SolveCell(puzzle, r + 1, 0))
return true;
}
else if (SolveCell(puzzle, r, c + 1))
return true;
return false;
}
private bool FindLastOne(Puzzle puzzle, int r, int c, Cell[] searchMe)
{
var numDashes = searchMe.Where(cell => cell.Value == '-')
.Count();
if (numDashes == 1)
{
puzzle.Cells[r, c].Value = puzzle.CharacterSet.Except( searchMe.Select(cell => cell.Value) )
.Single();
return true;
}
return false;
}
public bool SolvePuzzle(Puzzle puzzle)
{
bool tryAgain = true;
while (tryAgain)
{
tryAgain = false;
for (int i = 0; i < puzzle.TotalRows; i++)
for (int j = 0; j < puzzle.TotalRows; j++)
if (puzzle.Cells[i, j].Value == '-')
tryAgain = SolveCell(puzzle, i, j) ? true : tryAgain;
}
return IsSolved(puzzle);
}
private void loadToolStripMenuItem_Click(object sender, EventArgs e)
{
if(openFileDialog.ShowDialog() == DialogResult.OK)
{
puzzle = PuzzleReader.ReadPuzzle(openFileDialog.FileName);
if (puzzle != null)
{
RefreshPuzzle();
solveButton.Enabled = true;
}
else
MessageBox.Show("File is corrupted, check format.");
}
}
public override bool SolveCell(Puzzle puzzle, int r, int c)
{
return FindLastOne(puzzle, r, c, puzzle.BoxAt(r, c)) ||
FindLastOne(puzzle, r, c, puzzle.ColumnAt(c)) ||
FindLastOne(puzzle, r, c, puzzle.RowAt(r));
}
public static void WritePuzzle(string filename, Puzzle puzzle)
{
if (filename != null && puzzle != null)
File.WriteAllText(filename, puzzle.ToString());
}
public abstract bool SolveCell(Puzzle puzzle, int r, int c);
public void Init()
{
puzzle = new Puzzle(4, "1234", "42-1\n---2\n3-2-\n-4-3".Split());
}
public void Init()
{
puzzle = new Puzzle(4, "1234", rows);
}
public void Solve()
{
string[] solveMeRows = "4444\n----\n----\n----".Split();
Puzzle solveMePuzzle = new Puzzle(4, "1234", solveMeRows);
bool solved = solveMePuzzle.Solve();
Assert.IsFalse(solved);
}
