Feature #2: Evaluate the Arithmetic Expression

Description

For this feature, we have to create a module for evaluating mathematical expressions. The expressions are already extracted from the source code and are available as strings. Our job is to compute the result and return it. The expressions are subject to the following constraints:

• The numbers can only be integers.
• For simplicity’s sake, the expressions can only contain + and - operators.
• The expression can contain () parentheses.
• The expression has already been verified as being valid.

Let’s look at an example to understand the feature specifications. Suppose the input expression is "5-(3+4)". Our program has to evaluate it following mathematical rules. First, the expression inside parentheses is solved and then the rest. The result will be the integer value -2.