public BoardState Generate(BoardTemplate template)
{
if (template == null)
{
throw new ArgumentNullException(nameof(template));
}
int[] values = template.GetValues();
List<int> set = GetUnspecifiedValues(values);
List<int> unspecifiedIndices = GetUnspecifiedIndices(values);
foreach (int unspecifiedIndex in unspecifiedIndices)
{
int i = this.random.Next(0, set.Count);
values[unspecifiedIndex] = set[i];
set.RemoveAt(i);
}
if (!BoardValidator.IsSolvable(template.Width, template.Height, values))
{
int i = unspecifiedIndices[0];
int j = unspecifiedIndices[1];
if (values[i] == 0)
{
i = unspecifiedIndices[2];
}
else if (values[j] == 0)
{
j = unspecifiedIndices[2];
}
int temp = values[i];
values[i] = values[j];
values[j] = temp;
}
return new BoardState(template.Width, template.Height, values);
}
