Skip to main content

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_...
Post a Comment

C++ Day 20

 Day 20: Beginning with OOP-C++ Series

OOPs concepts in C# have always been reserved for Tuesdays as a prerequisite for teaching Complicated programming and real-time Representationing.


📚 Topic Covered:

🔹 1. what is oop

it is the system of amp plan into objects. Every object is an instance of a class.


🔹 2. shaping amp class

cpp

copy

edit

#include 

using namespace std;


class machine {

        public:

        train brand;

        int year;


        null displayinfo() {

                cout << "brand: " << mark << " year: " << class << endl;

        }

};

🔹 cardinal. Creating Objects

cpp

Copy

Edit

int main() {

    Car myCar;

    myCar.brand = "Toyota";

    myCar.year = 2020;

    myCar.displayInfo();

    return 0;

}

🔹 4. approach specifier:

public – away the family get work accessed


private – exclusive the family get work accessed


protected – exclusive the derivative classes get work accessed


🔹 v. Constructors: 

cpp

Copy

Edit

class Student {

public:

    string name;

    int roll;


    Student(string n int r) {

        name = n;

        roll = r;

    }


    void display() {

        cout << name << " - " << roll << endl;

Labels:

Comments

Post a Comment

Popular posts from this blog

C++ Day 35

  C++ Day 34: Layout Layouts (Part 2) We’ll cover: Constructer Layout Adjuster Layout Decorator Layout practise Task 🔹 1. developer form (creational) used to make compound objects measure away step ✅ employ case: you need to form associate in nursing aim (like amp pizza pie calculator house) with elective parameters example: cpp copy edit class calculator {     train Methodor gpu ram; public:     family developer {         train Methodor gpu ram;     public:         developer setcpu(string c) { Methodor = c; take *this; }         developer setgpu(string g) { gpu = g; take *this; }         developer setram(string r) { run = r; take *this; }         calculator Construct() {             take Calculater(cpu gpu ram);         }     };     Calculater(string snow train m train r) : cpu(c) gp...
Post a Comment
Read more

C++ Day 33

  C++ Day 33: Smart Pointers & Memory Management 🔹 1. wherefore forward pointers in c++ hand-operated green / cancel is error-prone: memory leaks 🧠 double deletes ❌ dangling pointers 💥 smart pointers care store mechanically exploitation raii (Supply skill is initialization) 🔹 ii. Types of Smart Pointers in C++ ✅ std::unique_ptr Sole ownership of a Supply. Cannot be copied. Automatically deletes the Supply when it goes out of scope. cpp Copy Edit #include  unique_ptr ptr1 = make_unique(10); cout << *ptr1 << endl; // 10 You can transfer ownership: cpp Copy Edit unique_ptr ptr2 = move(ptr1); ✅ std::shared_ptr Shared ownership multiple shared_ptrs can point to the same object. Uses reference counting to track how many owners. cpp Copy Edit shared_ptr p1 = make_shared(100); shared_ptr p2 = p1;  // Reference count = 2 When count goes to 0 memory is released. ✅ std::weak_ptr Non-owning reference to a shared_ptr-managed object. Used to break cyclic references ...
Post a Comment
Read more

CSES Increasing Subsequence solution

 You are given an array containing  n n n integers. Your task is to determine the longest increasing subsequence in the array, i.e., the longest subsequence where every element is larger than the previous one. A subsequence is a sequence that can be derived from the array by deleting some elements without changing the order of the remaining elements. Input The first line contains an integer n n n : the size of the array. After this there are n n n integers x 1 , x 2 , … , x n x_1,x_2,\ldots,x_n x 1 ​ , x 2 ​ , … , x n ​ : the contents of the array. Output Print the length of the longest increasing subsequence. Constraints 1 ≤ n ≤ 2 ⋅ 1 0 5 1 \le n \le 2 \cdot 10^5 1 ≤ n ≤ 2 ⋅ 1 0 5 1 ≤ x i ≤ 1 0 9 1 \le x_i \le 10^9 1 ≤ x i ​ ≤ 1 0 9 Example Input: 8 7 3 5 3 6 2 9 8 Output: 4 #include < bits / stdc ++. h > using namespace std ; void solve (){ int n ; cin >> n ; vector <int> arr ( n ); for ( int i = 0 ; i < n ; i ++)...
Post a Comment
Read more