Test whether two IEnumerable have the same values with the same frequencies

Question

I have two multisets, both IEnumerables, and I want to compare them.

string[] names1 = { \"tom\", \"dick\", \"harry\" };
string[] names2 = { \

Answer 1

You could use a binary search tree to ensure that the data is sorted. That would make it an O(log N) operation. Then you can run through each tree one item at a time and break as soon as you find a not equal to condition. This would also give you the added benefit of being able to first compare the size of the two trees since duplicates would be filtered out. I'm assuming these are treated as sets, whereby {"harry", "harry"} == {"harry").

If you are counting duplicates, then do a quicksort or a mergesort first, that would then make your comparison operation an O(N) operation. You could of course compare the size first, as two enums cannot be equal if the sizes are different. Since the data is sorted, the first non-equal condition you encounter would render the entire operation as "not-equal".