public static MultiSet <T> Difference(MultiSet <T> a, MultiSet <T> b)
{
Utils.ThrowException(a == null ? new ArgumentNullException("a") : null);
Utils.ThrowException(b == null ? new ArgumentNullException("b") : null);
MultiSet <T> c = new MultiSet <T>(a.Comparer); // *** inherits comparer from a (b is expected to have the same comparer)
foreach (KeyValuePair <T, int> item in a)
{
int bCount = b.GetCount(item.Key);
int cCount = item.Value - bCount;
if (cCount > 0)
{
c.mItems.Add(item.Key, cCount);
}
}
return(c);
}
public static MultiSet <T> Intersection(MultiSet <T> a, MultiSet <T> b)
{
Utils.ThrowException(a == null ? new ArgumentNullException("a") : null);
Utils.ThrowException(b == null ? new ArgumentNullException("b") : null);
MultiSet <T> c = new MultiSet <T>(a.Comparer); // *** inherits comparer from a (b is expected to have the same comparer)
if (b.Count < a.Count)
{
MultiSet <T> tmp; tmp = a; a = b; b = tmp;
}
foreach (KeyValuePair <T, int> item in a)
{
int bCount = b.GetCount(item.Key);
if (bCount > 0)
{
c.mItems.Add(item.Key, Math.Min(item.Value, bCount));
}
}
return(c);
}
public int GetCount(T item)
{
return(mSet.GetCount(item));
}