This is the final project for the "Computer programming" course (Fall 2016) at Shahid Beheshti University.
A class called BigInteger is implemented to do different mathematical operations for very large integers stored as strings. All related arithmetic, assignment, and relational operators are overloaded to fully support different mathematical operations without needing to memorize methods.
The UI is created using Qt. It also has a history panel to keep track of all calculations and their results.