Programming of two pillars arithmetic 2

Personal Item------Arithmetic 2

1. The topic avoids repetition.
2. Parameters can be controlled.
3. can be customized.

My design ideas:

1. is the implementation of the random number.
2. The interface defines the range of random numbers.
3. The interface definition has a variety of parameter definitions, and you can use case statements to know how many functions are required.
4. In order to avoid repetition, I define in each set of questions, repetition is not possible, but different sets of questions can be repeated, so the idea is as follows: In the limited range, the number of random items from small to large assignment, has been assigned to the array of items, then skip, until the full assignment, you can get a randomly ordered array, Take the number that you need earlier. So although the first number in each set of questions will not be the same, but this is a test question, you can guarantee that the topic will not be the same.
5. To be customizable, you can use the while loop to define how many times to print.

This is my design idea, hope can succeed.

Programming of two pillars arithmetic 2