C++ Roadmap

Learn C++ step by step — 45 free lessons with spaced repetition and active recall on RetainHQ, so what you study actually sticks.

Lessons

• Abstract classes & pure virtual functions
• accumulate, transform & common <algorithm> patterns
• Arrays, strings & C-style vs std::string
• auto, range-for & structured bindings (C++17)
• Bit manipulation tricks for CP
• Bitmask DP & subset enumeration
• Classes, constructors, destructors & this
• const correctness — const refs, const methods & when to use
• constexpr & compile-time computation
• Copy elision & RVO/NRVO
• CP template — fast I/O, macros & type aliases
• Custom comparators with lambda for sort/PQ
• Data types, I/O (cin/cout) & fast I/O tricks
• deque, list & array
• Disjoint Set Union (DSU) with path compression
• Fenwick tree (BIT) — prefix sums
• Functions — pass by value, reference & pointer
• GCD/LCM, Euler's totient, nCr mod p
• Implement vector, stack & LRU cache from scratch
• Inheritance & virtual functions / vtable
• Iterator invalidation — when containers reshuffle under you
• Lambda expressions & closures
• map & set — red-black tree, O(log n) ops
• Memory leaks, dangling pointers & double free
• Modular arithmetic & fast power
• Move semantics & rvalue references
• multimap, multiset & priority_queue
• next_permutation, rotate & reverse
• Operator overloading — common interview cases
• Preprocessor macros & #define for CP
• RAII — resource acquisition is initialization
• References vs pointers — syntax & mental model
• Rule of 3 / 5 / 0 - copy, move, destructor
• Segment tree — range query & point update
• Sieve of Eratosthenes & prime factorization
• sort, binary_search, lower_bound & upper_bound
• Sparse table & RMQ
• Stack vs heap — new/delete & memory layout
• std::optional, std::variant & std::any
• Templates — function & class templates
• undefined behaviour — common traps
• unique_ptr, shared_ptr & weak_ptr
• unordered_map & unordered_set — hash internals
• vector — internals, push_back amortization
• vtable, vptr & dynamic dispatch overhead