public Puzzle findBadMinimalPuzzle()
{
Puzzle workPuzzle = new Puzzle();
for (int i = 0; i < 9; i++)
{
for (int j = 0; j < 9; j++)
{
workPuzzle.values[i, j] = this.values[i, j];
}
}
for (int y = 0; y < 9; y++)
{
for (int x = 0; x < 9; x++)
{
//Check every location on the puzzle we're looking at to see if we can reduce it without making it non-unique
int oldValue = workPuzzle.values[x, y];
if (oldValue != 0)
{
workPuzzle.values[x, y] = 0;
if (!workPuzzle.isSolutionUnique())
{
workPuzzle.values[x, y] = oldValue;
}
}
}
//Console.WriteLine("row {0}", y);
}
return(workPuzzle);
}
//Returns a puzzle that:
//a) has a unique solution
//b) matches this puzzle except with one number removed
//if such a puzzle exists. If no such puzzle exists, return null.
public Puzzle findReducedPuzzle(int x, int y)
{
Puzzle reducedPuzzle = new Puzzle();
for (int i = 0; i < 9; i++)
{
for (int j = 0; j < 9; j++)
{
reducedPuzzle.values[j, i] = this.values[j, i];
}
}
if (this.values[x, y] != 0)
{
reducedPuzzle.values[x, y] = 0;
if (reducedPuzzle.isSolutionUnique())
{
return(reducedPuzzle);
}
}
return(null);
}
