public PuzzleGrid InitGrid()
{
PuzzleGrid tempGrid = new PuzzleGrid {
};
int row = 0;
int col = 0;
int newVal;
List <int> valueSet = new List <int>(Enumerable.Range(-9, 9));
List <int> valueSet2 = new List <int>();
Random rnd = new Random();
int randIndex = 0;
newVal = valueSet[randIndex];
tempGrid.InitSetCell(row, col, newVal);
valueSet.Remove(newVal);
for (row = 1; row < 9; row++)
{
randIndex = rnd.Next(0, valueSet.Count);
newVal = valueSet[randIndex];
valueSet2.Add(newVal);
valueSet.Remove(newVal);
tempGrid.InitSetCell(row, col, newVal);
}
row = 0;
for (col = 1; col < 3; col++)
{
randIndex = rnd.Next(0, valueSet.Count);
newVal = valueSet2[randIndex];
while ((newVal == tempGrid.Grid[1, 0] || (newVal == tempGrid.Grid[2, 0])))
{
randIndex = rnd.Next(0, valueSet2.Count);
newVal = valueSet2[randIndex];
}
valueSet2.Remove(newVal);
}
for (col = 3; col < 9; col++)
{
randIndex = rnd.Next(0, valueSet2.Count);
newVal = valueSet2[randIndex];
valueSet2.Remove(newVal);
tempGrid.InitSetCell(row, col, newVal);
}
for (col = 3; col < 9; col++)
{
randIndex = rnd.Next(0, valueSet2.Count);
newVal = valueSet2[randIndex];
valueSet2.Remove(newVal);
tempGrid.InitSetCell(row, col, newVal);
}
do
{
puzzleSolver = new PuzzleSolver();
puzzleSolver.SolveGrid((PuzzleGrid)tempGrid.Clone(), false);
SolutionGrid = puzzleSolver.SolutionGrid;
} while (SolutionGrid == null || SolutionGrid.IsBlank());
PermaGrid = Blanker(SolutionGrid);
return(PermaGrid);
}
public PuzzleGrid Blanker(PuzzleGrid solveGrid)
{
PuzzleGrid tempGrid;
PuzzleGrid saveCopy;
bool unique = true;
int totalBlanks = 0;
int tries = 0;
int desiredBlanks;
int symmetry = 0;
tempGrid = (PuzzleGrid)solveGrid.Clone();
Random rnd = new Random();
switch (difficulty)
{
case Difficulty.Easy:
desiredBlanks = 40;
break;
case Difficulty.Medium:
desiredBlanks = 45;
break;
case Difficulty.Hard:
desiredBlanks = 50;
break;
default:
desiredBlanks = 40;
break;
}
symmetry = rnd.Next(0, 2);
do
{
saveCopy = (PuzzleGrid)tempGrid.Clone();
tempGrid = RandomlyBlank(tempGrid, symmetry, ref totalBlanks);
puzzleSolver = new PuzzleSolver();
unique = puzzleSolver.SolveGrid((PuzzleGrid)tempGrid.Clone(), true);
if (!unique)
{
tempGrid = (PuzzleGrid)saveCopy.Clone();
tries++;
}
} while ((totalBlanks < desiredBlanks) && (tries < 1000));
solveGrid = tempGrid;
solveGrid.Finish();
return(solveGrid);
}
/// <summary>
/// SolveGrid attempts to solve a puzzle by checking through all
/// possible values for each cell, discarding values that do not lead
/// to a valid solution. On a try, it recursively calls itself to
/// maintain previous states of the grid to back track to if the
/// current path fails. It creates a local version of the grid to
/// facilitate this. It also checks if the puzzle is uniquely solvable.
/// </summary>
/// <param name="g">Current state of the grid</param>
/// <param name="checkUnique">Do we care if it has unique soln?</param>
/// <returns></returns>
public bool SolveGrid(PuzzleGrid g, bool checkUnique)
{
PuzzleGrid grid = new PuzzleGrid();
grid = (PuzzleGrid)g.Clone(); //Copy the input grid
int i, choice, r, c, numChoices;
bool done, got_one, solved, result;
got_one = false;
recursions++;
FillSingleChoices(grid); //First, fill in all single choice values
if (IsSolved(grid)) //If it's already solved
{
if (numSolns > 0) //If another soln already found
{
stoplooking = true; //Don't look for more
result = false; //Return false, no UNIQUE soln
}
else //If no other soln found yet
{
numSolns++;
final[numSolns] = (PuzzleGrid)g.Clone(); //Save found soln
result = true;
SolutionGrid = grid;
}
}
else //If not solved yet
{
if (!FindFewestChoices(grid, out r, out c, out numChoices))
{
result = false; //Invalid solution
}
else //Current grid still valid
{
i = 1;
done = false;
got_one = false;
while (!done && i <= numChoices)
{
choice = PickOneTrue(); //Pick a possible value
list[choice] = false; //Won't want to use it again
grid.UserSetCell(r, c, choice);
if (recursions < MaxDepth)
{
//-----------We must go deeper. SUDCEPTION!-----------//
solved = (SolveGrid(grid, checkUnique)); //Recurse
}
else
{
solved = false;
}
if (stoplooking == true)
{
done = true;
got_one = true;
}
else
{
got_one = (got_one || solved);
if (!checkUnique) //If not looking for unique soln
{
done = got_one; //Then we have a solution
}
}
i++;
}
result = got_one;
}
}
return(result);
}