C++ — Portfolio Projects
Build these to practice both C++'s OOP side and its STL/competitive-programming side — the two halves of the language that come up most in coursework, interviews, and contests.
Project 1: Inventory Management System With Classes (Beginner)
Time: 2-3 days
A console-based inventory tracker using proper class design — the project that gets you comfortable with constructors, encapsulation, and operator overloading before moving to more complex OOP.
Steps
Item class (name, quantity, price) with private members and public accessorsvector<< operator so you can cout << item directly instead of writing a separate print functionSkills Demonstrated
vector as a dynamic containerRepository Name
cpp-inventory-system
Project 2: A Small Library Using Inheritance and STL Containers (Intermediate)
Time: 4-5 days
Extend the beginner-level idea into a proper class hierarchy (base class + derived classes) and use STL containers (map, vector) meaningfully, not just as arrays with extra steps.
Steps
LibraryItem) with derived classes (Book, DVD, etc.) using virtual functions for behavior that differs per typemap (or smart-pointer equivalent) keyed by an ID for fast lookupunique_ptr/shared_ptr) over raw new/delete for ownershipSkills Demonstrated
vectorProject 3: Competitive-Programming Problem Set With Analysis (Advanced)
Time: 1-2 weeks
Solve 15-20 problems spanning arrays, STL usage, and at least one non-trivial algorithm topic (graphs, DP, or similar), then document your approach and complexity analysis for each — not just the accepted solution.
Steps
Skills Demonstrated
Repository Name
cpp-competitive-programming-log
Tips for Great Projects
Prefer STL over hand-rolled data structures, unless a project or problem specifically asks you to implement one yourself. Using vector/map/set correctly and knowing their real time complexity is the actual skill being tested, both in interviews and in contests.
Use smart pointers by default. If you find yourself writing new without an immediate, clear reason to manage that memory manually, reach for make_unique/make_shared instead — this is what real modern C++ code looks like.
Document your complexity analysis. "This solution passed" is weaker than "this is O(n log n) because of the sort, and I considered but rejected an O(n²) brute-force approach first."
For interviews specifically: be ready to explain when you'd use virtual functions vs. templates for two different types of "generic" behavior — this distinction (runtime polymorphism vs. compile-time generics) is a genuinely common C++ interview topic.
Project Checklist
vectornew/delete without a specific, explainable reason