Lesson 16: Master C++ STL Containers: vector, list, map & unordered_map

🗺️ The Standard Template Library (STL)

The C++ STL provides powerful, production-grade template data structures and algorithms.

📦 Key STL Containers Overview

⚡ std::vector<T>: Contiguous dynamic array with fast random access (O(1)).

🔗 std::list<T>: Doubly linked list with fast insertion/deletion anywhere (O(1)).

🌲 std::map<Key, Value>: Self-balancing Red-Black Tree keeping keys sorted (O(log N)).

⚡ std::unordered_map<K, V>: Hash table providing constant time lookup (O(1)).

🛡️ std::set<T>: Collection of unique sorted elements.

💻 Code Example: Key-Value Hash Map & Vector Operations

⊞C++ Source Code (main.cpp)

#include <iostream>

#include <unordered_map>

#include <string>

int main() {

std::unordered_map<std::string, double> productPrices;

productPrices["Intel Core i9"] = 589.99;

productPrices["NVIDIA RTX 4090"] = 1599.99;

productPrices["DDR5 32GB RAM"] = 129.99;

std::cout << "--- PC Component Prices (Hash Table Lookup) ---" << std::endl;

for (const auto &[item, price] : productPrices) {

std::cout << "📦 " << item << " => $" << price << std::endl;

}

return 0;

}

⊞Windows 11 Pro Terminal Execution OutputWindows 11 Pro Verified

⊞Administrator: Windows 11 Pro Command Prompt (g++ GCC 13.2.0)

—□✕

Microsoft Windows [Version 10.0.22631.3007] (Windows 11 Pro x86_64)

C:\Users\Student\CPP_Project>#include <iostream>

C:\Users\Student\CPP_Project> g++ -o main.exe main.cpp C:\Users\Student\CPP_Project> main.exe Hello World from C++ on Windows 11 Pro! [Process exited with code 0 in 0.001 seconds]

🗺️ The Standard Template Library (STL)

📦 Key STL Containers Overview

💻 Code Example: Key-Value Hash Map & Vector Operations

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