Describe the bug

TheIsAnagram function is not checking per-element counts. It is only checking if they have the same elements, but not if the count of each element matches.

A more appropriate name for the current logic is something likeContainsNoDifferingElements orIntersectsMatch rather thanIsAnagram. I would recommend changing the name or the logic of the method.

Note: If you aren't going to check per-element counts, then you should also get rid of this check inIsAnagrams:

if(source.Length!=other.Length)returnfalse;

because length doesn't matter if you don't also check per-element counts.

To Reproduce

Add the following case to theIsAnagram unit tests:

stringaab="aab";stringabb="abb";Assert.False(Permutations.IsAnargram(aab,abb));

Expected behavior

Spans of the same length and elements but different per-element counts should not be considered re-orders/anagrams of each other.

Environment:

master branch

Additional context

I have written my own version of this algorithm in C#(that fixes this issue) if interested here...

Source Code:https://github.com/ZacharyPatten/Towel/blob/d2660e208ad3a44ab22f192834760c5b93dc82ac/Sources/Towel/Statics-SequenceAnalysis.cs#L1321
Examples:https://github.com/ZacharyPatten/Towel/blob/d2660e208ad3a44ab22f192834760c5b93dc82ac/Examples/BasicsAndExtensions/Program.cs#L406
Testing:https://github.com/ZacharyPatten/Towel/blob/d2660e208ad3a44ab22f192834760c5b93dc82ac/Tools/Towel_Testing/Statics.cs#L2086
Note:MapHashLinked is my version of aDictionary if you look at the source code.