Kata

Please solve this puzzle, and fill your answer in the variable my_answer.

In this puzzle AT * A = CAT, a same letter represents a same digit, while different letters must represent different digits.

Since C and A appear at the beginning of numbers, either cannot be zero.

For example, if one guesses A = 3, T = 7, the answer will be wrong in that 37 * 3 = 111, but the product CAT is expected to be something like X37 (where X is not 0, 1, 3, or 7).

You can do it by pencil and paper.

You can also do it using programming language.

Simple codes are possible to complete the kata because the complexity is trivial. Why not loop?

More interesting algorithms are happily welcome:-)

On results

A partial solution as a string will pass. Please have one space at both sides of '*' and '=', and keep no trailing spaces at the end. Since we are talking about arithmetics, we use '=' instead of '=='.

For example: (this answer is incorrect) '37 * 3 = 111'

Full solutions are appreciated. Please return full solutions as a set, or a list, or a tuple, of strings formatted in the way above. Do not worry if your full solution is not complete or contains duplicates; they are also accepted. However, if a wrong entry is included, the whole full solution will be rejected.

On tests

If any entry of your solution pass ONE item in the check-list, there is a 'test passed' message; but I would not tell you what it is.