/// <summary>
/// Determines whether this collection contains the same count of the same elements as the specified collection.
/// </summary>
/// <param name="other">The collection to check this collection against.</param>
/// <returns>True if both collections contain the same count of the same elements; otherwise false.</returns>
public bool ContainsSameCountAs(CountingCollection <T> other)
{
Contracts.Requires.That(other != null);
// this is just an optimization
if (this == other)
{
return(true);
}
// This is both an optimization and ensures that both collections have the same set
// of KeyValuePairs given the foreach loop below. Without this check the foreach below
// would enumerate each KeyValuePair in this collection, but the other could contain
// more that we don't check.
if (other.Count != this.Count)
{
return(false);
}
foreach (var pair in this.countPerItem)
{
int countOfItem;
if (other.countPerItem.TryGetValue(pair.Key, out countOfItem))
{
// check if the count of the other collection's entry matches this collection's current entry count
if (countOfItem != pair.Value)
{
return(false);
}
}
else
{
// the other collection doesn't contain an entry to match this collection's current entry
return(false);
}
}
return(true);
}
/// <summary>
/// Subtracts the counts of items from the other collection from this collection.
/// </summary>
/// <param name="other">The other collection to subtract from this collection.</param>
public void SubtractCountFrom(CountingCollection <T> other)
{
Contracts.Requires.That(other != null);
foreach (KeyValuePair <T, int> entry in other.countPerItem)
{
// if this collection contains the item then subtract from it
int count;
if (this.countPerItem.TryGetValue(entry.Key, out count))
{
// this collection's item count equals itself minus the other collection's item count
count -= entry.Value;
if (count >= 1)
{
this.countPerItem[entry.Key] = count;
}
else
{
this.countPerItem.Remove(entry.Key);
}
}
}
}
