public static Sudoku.coords ReplaceRandom()
{
var coordinates = new Sudoku.coords();
int missing = hint_initializers();
int k = 0;
int rnd_pos = GetRandom();
for (int i = 0; i < 9; i++)
{
for (int j = 0; j < 9; j++)
{
if (Form1.cp_matrix[i, j] != hint_map[i, j])
{
k++;
if (k == rnd_pos)
{
Form1.cp_matrix[i, j] = hint_map[i, j];
coordinates.i = i;
coordinates.j = j;
return(coordinates);
}
}
}
}
return(coordinates);
}
//backtracking to get the solution of the Sudoku
public static void Rezolvare(int[,] matrix, Sudoku.coords coordinates)
{
if (CheckCompletition(matrix))
{
completed = true;
return;
}
for (int l = 1; l <= 9; l++)
{
if (Checking(matrix, coordinates, l))
{
matrix[coordinates.i, coordinates.j] = l;
if (completed == false)
{
Rezolvare(matrix, GetEmptyField(matrix));
}
if (completed == false)
{
matrix[coordinates.i, coordinates.j] = 0;
}
}
}
}
//method to return the first empty field
public static Sudoku.coords GetEmptyField(int [,] game_board)
{
var field = new Sudoku.coords();
for (field.i = 0; field.i < 9; field.i++)
{
for (field.j = 0; field.j < 9; field.j++)
{
if (game_board[field.i, field.j] == 0)
{
return(field);
}
}
}
return(field);
}
private void button82_Click(object sender, EventArgs e)
{
//The hint Button
var coordinates = new Sudoku.coords();
coordinates = Hint.ReplaceRandom();
Hint.hint_uses++;
buttons[coordinates.i, coordinates.j].Text = cp_matrix[coordinates.i, coordinates.j].ToString();
buttons[coordinates.i, coordinates.j].BackColor = Color.AliceBlue;
if (Hint.CheckCompletition(cp_matrix))
{
Form3 f3 = new Form3();
Hide();
stopwatch.Stop();
f3.ShowDialog();
Close();
return;
}
}
//checking if the number entered is correct
public static bool Checking(int [,] matrix, Sudoku.coords coordinates, int value)
{
bool row = true, collumn = true, square = true;
//checking row
for (int k = 0; k < 9; k++)
{
if (matrix[coordinates.i, k] == value)
{
row = false;
}
}
//checking collumn
for (int k = 0; k < 9; k++)
{
if (matrix[k, coordinates.j] == value)
{
collumn = false;
}
}
//checking square
int ii = (coordinates.i / 3) * 3;
int jj = (coordinates.j / 3) * 3;
for (int p = ii; p < ii + 3; p++)
{
for (int q = jj; q < jj + 3; q++)
{
if (matrix[p, q] == value)
{
square = false;
}
}
}
return(row & collumn & square);
}