제출 #14125

실행 실패 (제출 코드 컴파일 에러)

Main.java:11: error: incompatible types: cannot infer type arguments for HashSet<>
            list.putIfAbsent(str.length(), new HashSet<>());
                                                      ^
    reason: no instance(s) of type variable(s) E exist so that HashSet<E> conforms to List<String>
  where E is a type-variable:
    E extends Object declared in class HashSet
Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output
1 error