public void Validate(Board.SolutionType solutionType)
{
this.size = input.Count * input.Count - 1;
ValidateShape();
ValidateNumbers();
ValidateInversions(solutionType);
}
private void ValidateInversions(Board.SolutionType solutionType)
{
int numberOfInversions = CountNumberOfRegularInversions(input);
int numberOfInversionsSolution = CountNumberOfRegularInversions(solution);
int start0Index = -1;
int goal0Index = -1;
for (int i = 0; i < input.Count; i++)
{
start0Index = input[i].FindIndex(c => c == 0);
if (start0Index > -1)
{
start0Index = i * input.Count + start0Index;
break;
}
}
for (int i = 0; i < solution.Count; i++)
{
goal0Index = solution[i].FindIndex(c => c == 0);
if (goal0Index > -1)
{
goal0Index = i * solution.Count + goal0Index;
break;
}
}
if (input.Count % 2 == 0) // In this case, the row of the '0' tile matters
{
numberOfInversions += start0Index / input.Count;
numberOfInversionsSolution += goal0Index / solution.Count;
}
if (numberOfInversions % 2 != numberOfInversionsSolution % 2)
{
throw new ValidatorException("Unsolvable puzzle");
}
}
