simple cmd calc inspired by https://habr.com/ru/company/yandex/blog/206234/
Hello, this is a simple task from Yandex blog on habr. You have time about 2 hours and a white paper and then you need to implement a good working code. My first commit on this challenge - simple_calc.cpp. I've done some improvements in my code and created a simple project for linux/C++11 with Makefile: make all - build project; make simple - build first version