public bool ComputerNextSolution()
{
if (IsFinished())
{
return(true);
}
// next iteration
PositionValues val = FindNext();
int[] ints = val.Values;
if (ints.Length == 1)
{
// only one choice insert value - this solution is a success
sudukoMap[val.Pos.row, val.Pos.col] = ints[0];
return(true);
}
// more than one solution - try from the start
for (int i = 0; i < ints.Length; i++)
{
sudukoMap[val.Pos.row, val.Pos.col] = ints[i];
if (ComputerNextSolution())
{
return(true);
}
// else delete and try next
sudukoMap[val.Pos.row, val.Pos.col] = 0;
}
return(false);
}
public PositionValues FindNext()
{
PositionValues returnVar = new PositionValues(new Position(), null);
int minNo = 999; // number of possible values
Position pos = new Position();
for (int row = 0; row < 9; row++)
{
for (int col = 0; col < 9; col++)
{
pos.row = row;
pos.col = col;
int val = sudukoMap[row, col];
if (val == 0)
{ // no value in this posistion
List <int> missingNumbers = this.GetMissingNumbers(pos);
if (missingNumbers.Count < minNo)
{ // find the one with fewest alternatives optimal only one
minNo = missingNumbers.Count;
returnVar.Pos = pos;
returnVar.Values = missingNumbers.ToArray();
}
}
// if one posistion with only one posssible value - pick that
if (minNo == 1)
{
break;
}
}
if (minNo == 1)
{
break;
}
}
return(returnVar);
}