Thanks for this kata.
It was difficult, but very cool.
You are very helpful in developing thinking.
Thanks for such test cases.

Hi, i don't understand what is my mistake. I got this message: Expected actual value NaN to approximately equal expected value -193.81136244163088 (accepted relative error: 1e-9). I don't see test cases how example cata: https://www.codewars.com/kata/evaluate-mathematical-expression/. And i don't understand what cases i not processing. Can you help me?

Task was very intresting. I finded solution some days. On first step - i try get everything permutation, but if string length was advantage that 15 symbols my pc froze. On second step - i try find permutation using number permutation, but if i calc string with length advantage 20 symbols - i got measurement error, which influenced on calculations. On third stage - i saw, what i can using calculation withot factorial calculation. Thanks your for this task.