Write a method hasDuplicateValues
that, given a non-null
Map<String, String>
, returns true
if the map
contains duplicate values—meaning that two different keys map to the same value—and false
otherwise.
Recall that a map can never contain duplicate keys, since the second mapping from the same key overwrites the
first.
You should use a Set
to solve this problem!
You do not need to import
Map
, Set
, or HashSet
, since these are already provided for you.
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