write a program that takes three sets A, B and C as input. Then implement Question (a) and (b), and answer Question (c) as follows: (a) A B C (b) A B A C (c) Compare the results from (a) and (b), what conclusion can you draw from your observation? You may try different setups for A, B and C to confirm your conclusion.

There are some C++ algorithms doing the same operations (such as set union, set intersection et al.), but you are NOT allowed to use them. You must write your functions to implement these operations.

(2) To represent set in C++, you can use, but not restrict to, std:vector from the standard template library by using #include. More information about vector in C++ can be found at http://www.cplusplus.com/reference/vector/vector/