/// <summary>
/// Returns a new automaton that accepts strings representing decimal
/// non-negative integers in the given interval.
/// </summary>
/// <param name="min"> minimal value of interval </param>
/// <param name="max"> maximal value of interval (both end points are included in the
/// interval) </param>
/// <param name="digits"> if >0, use fixed number of digits (strings must be prefixed
/// by 0's to obtain the right length) - otherwise, the number of
/// digits is not fixed </param>
/// <exception cref="IllegalArgumentException"> if min>max or if numbers in the
/// interval cannot be expressed with the given fixed number of
/// digits </exception>
public static Automaton MakeInterval(int min, int max, int digits)
{
Automaton a = new Automaton();
string x = Convert.ToString(min);
string y = Convert.ToString(max);
if (min > max || (digits > 0 && y.Length > digits))
{
throw new System.ArgumentException();
}
int d;
if (digits > 0)
{
d = digits;
}
else
{
d = y.Length;
}
StringBuilder bx = new StringBuilder();
for (int i = x.Length; i < d; i++)
{
bx.Append('0');
}
bx.Append(x);
x = bx.ToString();
StringBuilder by = new StringBuilder();
for (int i = y.Length; i < d; i++)
{
by.Append('0');
}
by.Append(y);
y = by.ToString();
ICollection <State> initials = new List <State>();
a.Initial = Between(x, y, 0, initials, digits <= 0);
if (digits <= 0)
{
List <StatePair> pairs = new List <StatePair>();
foreach (State p in initials)
{
if (a.Initial != p)
{
pairs.Add(new StatePair(a.Initial, p));
}
}
BasicOperations.AddEpsilons(a, pairs);
a.Initial.AddTransition(new Transition('0', a.Initial));
a.deterministic = false;
}
else
{
a.deterministic = true;
}
a.CheckMinimizeAlways();
return(a);
}
