How do I fix 'iterator invalidation' bugs in C++?

Iterator invalidation occurs when an algorithm modifies a container, which causes existing iterators to become invalid. To fix these bugs, you can follow several strategies:

• Use appropriate containers: Some containers, like std::vector, have iterator invalidation rules. Understanding these rules can help you avoid issues.
• Reserve space: In dynamic containers like std::vector, use the reserve() function to allocate memory ahead of time, minimizing changes that could invalidate iterators.
• Use index-based loops: Instead of using iterators directly, consider using index-based loops, especially when you need to modify the container within the loop.
• Recalculate iterators: If you must modify a container, make sure to recalculate iterators after modification.
• Use container member functions: Many container classes have member functions that return iterators safely without invalidating existing ones.

By applying these strategies, you can effectively manage iterator invalidation and avoid runtime errors in your C++ programs.