Solve bank, password, expression algorithm tasks

Overview

This question evaluates algorithmic implementation and system-design skills across stateful banking operations, password-processing algorithms (validation and strength), and arithmetic expression parsing, testing competencies in data structures, parsing techniques, string manipulation, state management, and correctness under constraints in the Coding & Algorithms domain. It is commonly asked in technical interviews because it reveals the ability to produce practical implementations that handle input validation, edge cases, efficient parsing and evaluation, and overall robustness, emphasizing practical application over purely conceptual understanding.