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C++ Day 39

  C++ Day 39 STL Containers (Deep Understanding & Real Usage) Till now, you already know arrays, vectors, loops, and STL algorithms. Today, we go one step deeper and understand STL containers , which are the backbone of modern C++ programming. In real projects and competitive coding, choice of container matters a lot. 1. What are STL Containers? STL containers are data structures provided by C++ to store data efficiently. They handle: memory management resizing element access performance optimization You focus on logic , not memory handling. 2. Categories of STL Containers STL containers are mainly divided into: Sequence Containers Associative Containers Unordered Containers Container Adapters 3. Sequence Containers These store data in sequence . 3.1 Vector Most used container in C++. vector< int > v; Key Features: Dynamic size Contiguous memory Fast random access Slower insertion in middle Example: v. push_...
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C++ Day 15

 C ++ day 15: polymorphism and virtual work

🔹 1. What is polymorphism? Polytestrality = "many forms". In C ++, it is mainly obtained: Ceremony surcharge (pre -covered) Ceremony overriding Virtual work 🔹 2. Function Overroid (Ricap) CPP Copy edit Class base { public: Zero greetings () {cout << "Hello base \ n"; , , Class derivative: Public base { public: Zero greetings () {cout << "Hello derived \ n"; , , 🔹 3. Virtual work Runtime allows polymorphism. Call the correct function through base class pointer/reference. CPP Copy edit Class animal { public: Virtual zero sound () { cout << "Animal sound \ N"; , , Class Dog: Public Animal { public: Zero sound () override { cout << "dog barks \ n"; , , int main() { Animal* a = new dog (); A-> sound (); // Dog bark Remove A; , 🔹 4. Pure virtual work and abstract class CPP Copy edit Class size { public: Virtual zero draw () = 0; // Pure virtual , Class Circle: Public Size { public: Zero Draw () Overrid { cout << "drawing circle \ n"; , , 🔹 5. Virtual distractor Always use virtual destroyers if your class is inherited. CPP Copy edit Class base { public: Virtual ~ base () { cout << "base destroying \ n"; , , 🧠 Day 15 Practice Create a class animal with virtual speech () function. Overred it into a cat, dog and cow. Create an abstract square shape with a pure virtual function area (). Get the rectangle and circle, and apply the area () in both. Create a base indicator pointing to a derivative object. Call a virtual and non-natural method and observe behavior.
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C++ Day 35

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C++ Day 33

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CSES Increasing Subsequence solution

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