Looking at the way most of the students have approached the problem, I have given two solutions to the project with a hope that your approach closely approximates one of the two solutions. The solutions are also in 22c16 folder in the nebula server .
The first approach is to handle two operators at a time. It proceeds by handling all the combinations of the two operators. We also have only two operands in picture which are initially assigned with the first two operands. But these operands are changed as new operands are fetched and finally the first operand yields the result. Here is the solution The second approach does not handle two operators at the same time. It uses a temperorary variable instead. The result is calculated by adding either the operand (if between two + symbols) or the product of operands. The temporary is used to hold the product. Here is the second solution