Implement iterator

Implementing random-access iterators for a custom container

This easy coding problem tests your ability to design and implement iterator semantics for a custom wrapper class. It is representative of design-pattern and generic-programming questions that appear in C++ interview rounds, particularly where candidates are expected to work with existing codebases that rely on standard library conventions.

The problem requires you to implement the core operations that make an iterator work with standard C++ patterns: increment operators, dereferencing, equality comparison, and constructor logic. The key is understanding which operators are essential for range-based for-loops and random-access semantics, and implementing them cleanly without modifying the underlying container logic. Interviewers typically follow up by asking about const-correctness, operator overload placement, or how your iterator would interact with standard algorithms like std::sort.

• Iterator traits and categories (input, forward, bidirectional, random-access)
• Pre-increment vs. post-increment trade-offs
• Const and non-const iterator variants
• Pointer arithmetic and dereferencing