Stack-based-Calculator

Overview

This program implements a calculator that performs mathematical operations using a stack-based approach. It processes mathematical expressions like addition, subtraction, multiplication, division, exponentiation, and factorials. The program utilizes a custom LinkedStack class to manage operations and follows standard operator precedence rules.

Features

• Basic Arithmetic : Supports addition, subtraction, multiplication, division, and exponentiation.
• Factorial Calculation : Computes the factorial of integers.
• Parentheses Handling : Handles expressions with parentheses correctly.
• Constants : Supports constants like Euler's number (e) and pi (p).
• Operator Precedence : Correctly evaluates operations in the order of precedence using stacks.

Key Methods

1. fillStack():

   • Fills the stack with the individual elements of the input expression.
   • Validates the expression and ensures that the operators and operands are in a valid sequence.

2. factorial(int n):

   • Computes the factorial of a given integer n.

3. calcPowers():

   • Evaluates exponentiation (^) operations.

4. calcMulAndDiv():

   • Handles multiplication (x) and division (/) operations.

5. calcPlusAndSub():

   • Handles addition (+) and subtraction (-) operations.

6. calculate():

   • The main calculation function that processes the input expression and returns the result.
   • It manages the entire sequence of operations by calling helper functions like calcPowers, calcMulAndDiv, and calcPlusAndSub.

Error Handling

• The calculator throws an exception if the input expression contains invalid characters or malformed operations. For example:
  • Operators cannot be placed at the beginning or end of an expression.
  • Invalid usage of factorial (!) or mismatched parentheses will throw an exception.

Input Format

• The input is a string containing the mathematical expression to be evaluated.
• Operators: +, -, x, /, ^, !
• Constants: e for Euler's number, p for pi
• Parentheses: () for grouping
• Example: "3+5*(2^3)-6"

Output Format

• The output will be the result of the expression after evaluation.

Dependencies

• The program requires a LinkedStack class that is used to manage the stack operations. Ensure this class is defined in your project.