Explain C++ containers, segfaults, and virtual dispatch

Answer the following C++ conceptual questions: 1. **C++ standard containers implementation** For common C++ standard library containers such as `std::vector`, `std::list`, `std::map`, and `std::unordered_map`: - What are their typical underlying data structures and memory layouts? - What are their key performance characteristics (time complexity of insert, erase, random access, iteration)? - In what scenarios would you prefer one container over another? 2. **Segmentation fault causes** In C or C++, what is a segmentation fault, and in what typical situations can it occur? Give several concrete examples involving pointers, arrays, and memory management. 3. **Virtual constructors in C++** Can a constructor in C++ be declared as `virtual`? Why or why not? Explain the language and object model reasons behind this, and mention common patterns used when people think they "need" a virtual constructor. 4. **How virtual functions find the correct implementation** How does C++ implement virtual function dispatch under the hood? Explain how the program decides at runtime which overridden function to call when you invoke a virtual method through a base-class pointer or reference. Include in your explanation: - The roles of the vtable and vptr (or equivalent mechanisms). - What happens with single inheritance vs. multiple inheritance at a high level. - Any special considerations during construction and destruction.