Write a simple C++ code

I need an experienced C++ developer to write a code on their own without using any online sources. It's a simple C++ project and you need to extend on an already given source code. The program reads in the arithmetic expression and encodes the expression as a binary tree. After the expression has been read in, the variable assignments are read in and the variables and their values of the variables are placed into the symbol table. Finally the expression is evaluated recursively. Please go through the attachment for more information. Thanks!