According to Sheldon Cooper the best number is 73, because 73 is the 21st prime number. Its mirror, 37, is the 12th prime number. 21 is the product of multiplying 7 by 3 and in binary, 73 is a palindrome: 1001001

Sheldon Cooper (character in the famous series "The Big-Bang Theory")

This is a repository that will take you by the hand in the 73 most useful LeetCode problems, well they are actually 76, 😬 the algorithms are written in C, C++ and C#, I wrote each program in the most optimal way and included the main function or method of the program to test on your machine, a README file with solution notes and for problems 252, 253, 269, 271 and 323 being Premium subscription problems, I included a README with the description of each problem. 🤓

No hurry, but no rest

The repository is divided into 4 folders:

|- Repository
    |- .vscode
        |- tasks.json
    |- Problems
        |- Arrays
        |- Matrix
            |- Rotate-Image
                |- Rotate-Image.c
                |- Rotate-Image.cpp
                |- Rotate-Image.cs
                |- Rotate-Image.csproj
                |- README.md
            |- Set-Matrix-Zeroes
            |- Spiral-Matrix
            |- Word-Search
        |- Strings
        |- Intervals
        |- Binary Search
        |- Dynamic Programming
        |- Linked Lists
        |- Trees
        |- Heaps
        |- Graphs
    |- Sources
        |- Sheldon.gif

• .vscode: Contains the 'tasks.json' file that configures the build task in Visual Studio Code for /usr/bin/g++ and the configuration for the output generated ${fileDirname}\\${fileBasenameNoExtension}.out

• Problems: Contains the folders for each topic, inside it has a folder per problem and inside each folder is the source code and the README that explains the problem, for example the Two-Sum folder contains the C source code Two-Sum.c (Only in the first problem of each topic there is an implementation in C language to go a little deeper), the C++ source code Two-Sum .cpp, the C# source code in Two-Sum.cs and the .NET project settings in Two-Sum.csproj and finally the README.md file

• Sources: Contains the images and gifs used in the repository, such as Sheldon Cooper's 😁 gif

The focus of this repository is towards C#, so you can use it from Windows, Linux, Mac, Docker or even GitHub Codespaces, but it is intended to be used on Linux, specifically a Ubuntu-based distribution, no matter if it is a complete distro or a WSL distro. Solutions in C (only the first problem of each topic) and C++ are also included , so to use this repository you must have installed:

To compile C and C++ you need to install gcc and g++

• gcc
• g++

To install them on Debian based distributions you can type:

Debian based distributions:

sudo apt update && \
    sudo apt install build-essential -y

If you want use this repository with C# then you should install dotnet-sdk-8.0

• dotnet-sdk-8.0

At this time the .NET 8 is only available from Ubuntu feed for Ubuntu 23.10, so, to install you can copy and paste the following commands:

Ubuntu 23.10:

sudo apt update && \
    sudo apt install dotnet-sdk-8.0 -y

Note: To install on other linux versions or linux distributions, please check this page.

• C
• C#
• C++
• Ubuntu
• VS Code

• High Speed History of C#
• Mono Edge - Miguel de Icaza
• .NET at Stack Overflow | .NET Conf 2022
• Miguel de Icaza's Vision Keynote - UnoConf 2019
• Full stack web UI with Blazor in .NET 8 | .NET Conf 2023
• Patterns for high-performance C# - Federico Andres Lois
• Let's design a new C# language feature! | .NET Conf 2022
• Adam SITNIK: Solving .NET performance issues | UCP2019
• What’s Next in C#? - Mads Torgersen - Copenhagen DevFest 2023
• S101 - Keynote with Scott Hunter, Mads Torgersen, and Miguel De Icaza
• The functional journey of C# - Mads Torgersen - NDC Copenhagen 2022
• Stop using Entity Framework as a DTO provider! - Chris Klug - NDC Oslo 2023
• You are doing logging in .NET wrong. Let’s fix it. - Nick Chapsas - NDC Oslo 2023
• .NET Systems Programming Learned the Hard Way - Aaron Stannard - NDC Oslo 2023
• Keynote: The Microsoft Open Source Cinematic Universe - Phase 2 - Scott Hanselman
• Using C# Source Generators to Build a .NET IoT Device - Alon Fliess - NDC Melbourne 2022
• Patterns for application development with ASP.NET Core - Damian Edwards & David Fowler
• Performance tricks I learned from contributing to open source .NET packages - Daniel Marbach
• Real-world examples on optimizing .NET performance - Stefán Jökull Sigurðarson - NDC Oslo 2023

• Pontus Nyman: C++ in Space
• Bjarne Stroustrup - The Essence of C++
• CppCon 2015: Kate Gregory “Stop Teaching C"
• Bjarne Stroustrup: C++ | Lex Fridman Podcast #48
• Bjarne Stroustrup: Why you should avoid Linked Lists
• Keynote: C++'s Superpower - Matt Godbolt - CPPP 2021
• CppCon 2016: Jason Turner “Practical Performance Practices"
• Can C++ be 10x Simpler & Safer? - Herb Sutter - CppCon 2022
• C++ in Constrained Environments - Bjarne Stroustrup - CppCon 2022
• Keynote: "Am I A Good Programmer?" - Kate Gregory - CppNorth 2022
• CppCon 2017: Bjarne Stroustrup “Learning and Teaching Modern C++”
• CppCon 2017: Peter Goldsborough “A Tour of Deep Learning With C++”
• CppCon 2017: Louis Brandy “Curiously Recurring C++ Bugs at Facebook”
• CppCon 2018: Peter Goldsborough “Machine Learning in C++ with PyTorch”
• CppCon 2014: Herb Sutter "Back to the Basics! Essentials of Modern C++ Style"
• CppCon 2016: Bjarne Stroustrup "The Evolution of C++ Past, Present and Future"
• The Most Important Optimizations to Apply in Your C++ Programs - Jan Bielak - CppCon 2022
• Trading at light speed: designing low latency systems in C++ - David Gross - Meeting C++ 2022
• CppCon 2018: Gordon Brown “A Modern C++ Programming Model for GPUs using Khronos SYCL”
• The Imperatives Must Go! [Functional Programming in Modern C++] - Victor Ciura - CppCon 2022
• Bjarne Stroustrup's Closing Keynote at Code Europe 2022 in Cracow – "How to evolve a language"
• Writing Safety Critical Automotive Software for High Perf AI Hardware - Michael Wong - CppCon 2019

Cppreference.com. (s. f.). https://en.cppreference.com/w/

Eckel, B. (2004). Thinking in C++. Thinking in C++ (2nd ed.). Pearson.

C# Docs - Get started, Tutorials, reference. https://learn.microsoft.com/en-us/dotnet/csharp/

Cormen, T. H., Leiserson, C. E., Rivest, R. L. & Stein, C. (2009). Introduction to Algorithms (3rd ed.). MIT Press.

Written with ❤️ by Jonas Lara for anyone who is interested