Competitive programming

Stage 1 · Lesson 2 of 7

Compiler, editor and flags

C++ for contests

Install a C++ compiler, usually (the GNU compiler), and an editor you like, such as VS Code. On Windows, WSL (a Linux environment inside Windows) or MSYS2 gives you g++ easily; on macOS and Linux it is a short install. Compile from the terminal with warnings on, and learn a second command with : compiler options that stop the program with a message when you read outside an array or overflow an integer.

Keep a folder per contest with a file per problem and an input file for the samples. Choose the same C++ standard, such as C++20, that your judge offers.

Common traprelying on an online IDE, where you cannot use sanitizers and lose your code when the tab closes.

A question to check yourself, an AI practice session and 1 cheat sheet entry come with the full roadmap. Unlock

Resources for this stage

Start with· follow one of these

  • CourseFree
    LearnCpp.com

    LearnCpp.com · Beginner

    Free and thorough: read the chapters on vectors, references, lambdas and the standard library if C++ is new to you

  • BookFree
    Competitive Programmer's Handbook

    Antti Laaksonen · Beginner

    Chapter 1 covers C++ for contests, input and output and working with numbers; Chapter 2 covers complexity

Practise

  • CSES Problem Set

    Start with the Introductory Problems section: short tasks that exercise loops, strings and the STL

  • Codeforces

    Filter the problem set to rating 800 and solve a few each day to get used to contest input and output

Keep handy

  • cppreference.com

    Keep it open for exact signatures and complexities of vector, set, map, sort and lower_bound

Also worth your time

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