The find_duplicates assignment.

11-find_duplicates/cpp/Makefile

11-find_duplicates/cpp/find_duplicates.h

11-find_duplicates/cpp/find_duplicates_test.cpp

11-find_duplicates/cpp/test_main.cpp

11-find_duplicates/python/find_duplicates.py

11-find_duplicates/python/find_duplicates_test.py

11-find_duplicates/task.md