static bool TestDeque(IDeque <int> deque, int n)
{
if (deque.Size != 0)
{
return(false);
}
for (int i = 0; i < n; i++)
{
deque.Prepend(i);
deque.Append(i);
deque.RemoveFirst();
}
if (deque.Size != n)
{
return(false);
}
if (n > 0 && (deque.First != 0 || deque.Last != n - 1))
{
return(false);
}
int elem = -1;
for (int i = 0; i < n; i++)
{
elem = deque.RemoveLast();
}
if (deque.Size != 0 || elem != 0)
{
return(false);
}
return(true);
}