Ran out of time and resorted to pseudo code.
Use a stack-based approach to handle nested parentheses and operator precedence. Iterate through the expression, maintaining a stack of previous results and signs, and a running result for the current parenthesis level. When encountering a digit, parse the full number and apply the current operator to the running result.
Pro tip: Clarify edge cases upfront, such as negative numbers, spaces, and division by zero, to show thoroughness. Also, mention that you can extend the solution to support more operators or functions if needed.
Ask about input format (e.g., spaces, negative numbers, division by zero) and expected output. Confirm that the calculator should follow standard operator precedence and handle nested parentheses.
Decide on a stack-based approach to manage nested expressions and operator precedence. Alternatively, consider recursion or two-stack (operands and operators) methods.
Describe how to iterate through the string, parse numbers, handle operators, and manage parentheses using a stack. Explain how to update the result and sign when encountering '(' and ')'.
Write clean code with meaningful variable names. Test with simple and complex expressions, including nested parentheses and multiple operators.
State time and space complexity (O(n) time, O(n) space for stack). Discuss potential optimizations or alternative approaches if relevant.
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