Invert keys and values in C#
C# interview exercise on Dictionaries & Sets, difficulty 1 of 3. Solve it in the editor beside a worked example; the tests run the moment you do.
Write Invert(d) that swaps keys and values. When two keys share a value, the one added later wins. ToDictionary throws on a duplicate key, so this needs a loop and the indexer, which overwrites.
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