A list of practical projects that anyone can solve in any programming language (See solutions). These projects are divided into multiple categories, and each category has its own folder. To get started, simply fork this repo. CONTRIBUTING See ways of contributing to this repo. You can contribute solutions (will be published in this repo) to existing problems, add new projects, or remove existing ones. Make sure you follow all instructions properly. Solutions You can find implementations of these projects in many other languages by other users in this repo. Credits Problems are motivated by the ones shared at: Martyr2’s Mega Project List Rosetta Code Table of Contents Numbers Classic Algorithms Graph Data Structures Text Networking Classes Threading Web Files Databases Graphics and Multimedia Security Numbers Find PI to the Nth Digit - Enter a number and have the program generate PI up to that many decimal places. Keep a limit to how far the program will go. Find e to the Nth Digit - Just like the previous problem, but with e instead of PI. Enter a number and have the program generate e up to that many decimal places. Keep a limit to how far the program will go. Fibonacci Sequence - Enter a number and have the program generate the Fibonacci sequence to that number or to the Nth number. Prime Factorization - Have the user enter a number and find all Prime Factors (if there are any) and display them. Next Prime Number - Have the program find prime numbers until the user chooses to stop asking for the next one. Find Cost of Tile to Cover W x H Floor - Calculate the total cost of the tile it would take to cover a floor plan of width and height, using a cost entered by the user. Mortgage Calculator - Calculate the monthly payments of a fixed-term mortgage over given Nth terms at a given interest rate. Also, figure out how long it will take the user to pay back the loan. For added complexity, add an option for users to select the compounding interval (Monthly, Weekly, Daily, Continually). Change Return Program - The user enters a cost and then the amount of money given. The program will figure out the change and the number of quarters, dimes, nickels, pennies needed for the change. Binary to Decimal and Back Converter - Develop a converter to convert a decimal number to binary or a binary number to its decimal equivalent. Calculator - A simple calculator to do basic operators. Make it a scientific calculator for added complexity. Unit Converter (temp, currency, volume, mass, and more) - Converts various units between one another. The user enters the type of unit being entered, the type of unit they want to convert to, and then the value. The program will then make the conversion. Alarm Clock - A simple clock where it plays a sound after X number of minutes/seconds or at a particular time. Distance Between Two Cities - Calculates the distance between two cities and allows the user to specify a unit of distance. This program may require finding coordinates for the cities like latitude and longitude. Credit Card Validator - Takes in a credit card number from a common credit card vendor (Visa, MasterCard, American Express, Discoverer) and validates it to make sure that it is a valid number (look into how credit cards use a checksum). Tax Calculator - Asks the user to enter a cost and either a country or state tax. It then returns the tax plus the total cost with tax. Factorial Finder - The Factorial of a positive integer, n, is defined as the product of the sequence n, n-1, n-2, ...1, and the factorial of zero, 0, is defined as being 1. Solve this using both loops and recursion. Complex Number Algebra - Show addition, multiplication, negation, and inversion of complex numbers in separate functions. (Subtraction and division operations can be made with pairs of these operations.) Print the results for each operation tested. Happy Numbers - A happy number is defined by the following process. Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy numbers, while those that do not end in 1 are unhappy numbers. Display an example of your output here. Find the first 8 happy numbers. Number Names - Show how to spell out a number in English. You can use a preexisting implementation or roll your own, but you should support inputs up to at least one million (or the maximum value of your language's default bounded integer type if that's less). Optional: Support for inputs other than positive integers (like zero, negative integers, and floating-point numbers). Coin Flip Simulation - Write some code that simulates flipping a single coin however many times the user decides. The code should record the outcomes and count the number of tails and heads. Limit Calculator - Ask the user to enter f(x) and the limit value, then return the value of the limit statement Optional: Make the calculator capable of supporting infinite limits. Fast Exponentiation - Ask the user to enter 2 integers a and b and output a^b (i.e. pow(a,b)) in O(LG n) time complexity. Classic Algorithms Collatz Conjecture - Start with a number n > 1. Find the number of steps it takes to reach one using the following process: If n is even, divide it by 2. If n is odd, multiply it by 3 and add 1. Sorting - Implement two types of sorting algorithms: Merge sort and bubble sort. Closest pair problem - The closest pair of points problem or closest pair problem is a problem of computational geometry: given n points in metric space, find a pair of points with the smallest distance between them. Sieve of Eratosthenes - The sieve of Eratosthenes is one of the most efficient ways to find all of the smaller primes (below 10 million or so). Graph Graph from links - Create a program that will create a graph or network from a series of links. Eulerian Path - Create a program that will take as an input a graph and output either an Eulerian path or an Eulerian cycle, or state that it is not possible. An Eulerian path starts at one node and traverses every edge of a graph through every node and finishes at another node. An Eulerian cycle is an eulerian Path that starts and finishes at the same node. Connected Graph - Create a program that takes a graph as an input and outputs whether every node is connected or not. Dijkstra’s Algorithm - Create a program that finds the shortest path through a graph using its edges. Minimum Spanning Tree - Create a program that takes a connected, undirected graph with weights and outputs the minimum spanning tree of the graph i.e., a subgraph that is a tree, contains all the vertices, and the sum of its weights is the least possible. Data Structures Inverted index - An Inverted Index is a data structure used to create full-text search. Given a set of text files, implement a program to create an inverted index. Also, create a user interface to do a search using that inverted index which returns a list of files that contain the query term/terms. The search index can be in memory. Text Fizz Buzz - Write a program that prints the numbers from 1 to 100. But for multiples of three print “Fizz” instead of the number and for the multiples of five print “Buzz”. For numbers which are multiples of both three and five print “FizzBuzz”. Reverse a String - Enter a string and the program will reverse it and print it out. Pig Latin - Pig Latin is a game of alterations played in the English language game. To create the Pig Latin form of an English word the initial consonant sound is transposed to the end of the word and an ay is affixed (Ex.: "banana" would yield anana-bay). Read Wikipedia for more information on rules. Count Vowels - Enter a string and the program counts the number of vowels in the text. For added complexity have it report a sum of each vowel found. Check if Palindrome - Checks if the string entered by the user is a palindrome. That is that it reads the same forwards as backward like “racecar” Count Words in a String - Counts the number of individual words in a string. For added complexity read these strings in from a text file and generate a summary. Text Editor - Notepad-style application that can open, edit, and save text documents. Optional: Add syntax highlighting and other features. RSS Feed Creator - Given a link to RSS/Atom Feed, get all posts and display them. Quote Tracker (market symbols etc) - A program that can go out and check the current value of stocks for a list of symbols entered by the user. The user can set how often the stocks are checked. For CLI, show whether the stock has moved up or down. Optional: If GUI, the program can show green up and red down arrows to show which direction the stock value has moved. Guestbook / Journal - A simple application that allows people to add comments or write journal entries. It can allow comments or not and timestamps for all entries. Could also be made into a shoutbox. Optional: Deploy it on Google App Engine or Heroku or any other PaaS (if possible, of course). Vigenere / Vernam / Ceasar Ciphers - Functions for encrypting and decrypting data messages. Then send them to a friend. Regex Query Tool - A tool that allows the user to enter a text string and then in a separate control enter a regex pattern. It will run the regular expression against the source text and return any matches or flag errors in the regular expression. Networking FTP Program - A file transfer program that can transfer files back and forth from a remote web sever. Bandwidth Monitor - A small utility program that tracks how much data you have uploaded and downloaded from the net during the course of your current online session. See if you can find out what periods of the day you use more and less and generate a report or graph that shows it. Port Scanner - Enter an IP address and a port range where the program will then attempt to find open ports on the given computer by connecting to each of them. On any successful connections mark the port as open. Mail Checker (POP3 / IMAP) - The user enters various account information include web server and IP, protocol type (POP3 or IMAP), and the application will check for email at a given interval. Country from IP Lookup - Enter an IP address and find the country that IP is registered in. Optional: Find the Ip automatically. Whois Search Tool - Enter an IP or host address and have it look it up through whois and return the results to you. Site Checker with Time Scheduling - An application that attempts to connect to a website or server every so many minute or a given time and check if it is up. If it is down, it will notify you by email or by posting a notice on the screen. Classes Product Inventory Project - Create an application that manages an inventory of products. Create a product class that has a price, id, and quantity on hand. Then create an inventory class that keeps track of various products and can sum up the inventory value. Airline / Hotel Reservation System - Create a reservation system that books airline seats or hotel rooms. It charges various rates for particular sections of the plane or hotel. For example, first class is going to cost more than a coach. Hotel rooms have penthouse suites which cost more. Keep track of when rooms will be available and can be scheduled. Company Manager - Create a hierarchy of classes - abstract class Employee and subclasses HourlyEmployee, SalariedEmployee, Manager, and Executive. Everyone's pay is calculated differently, research a bit about it. After you've established an employee hierarchy, create a Company class that allows you to manage the employees. You should be able to hire, fire, and raise employees. Bank Account Manager - Create a class called Account which will be an abstract class for three other classes called CheckingAccount, SavingsAccount, and BusinessAccount. Manage credits and debits from these accounts through an ATM-style program. Patient / Doctor Scheduler - Create a patient class and a doctor class. Have a doctor that can handle multiple patients and set up a scheduling program where a doctor can only handle 16 patients during an 8 hr workday. Recipe Creator and Manager - Create a recipe class with ingredients and put them in a recipe manager program that organizes them into categories like desserts, main courses, or by ingredients like chicken, beef, soups, pies, etc. Image Gallery - Create an image abstract class and then a class that inherits from it for each image type. Put them in a program that displays them in a gallery-style format for viewing. Shape Area and Perimeter Classes - Create an abstract class called Shape and then inherit from it other shapes like diamond, rectangle, circle, triangle, etc. Then have each class override the area and perimeter functionality to handle each shape type. Flower Shop Ordering To Go - Create a flower shop application that deals in flower objects and use those flower objects in a bouquet object which can then be sold. Keep track of the number of objects and when you may need to order more. Family Tree Creator - Create a class called Person which will have a name, when they were born, and when (and if) they died. Allow the user to create these Person classes and put them into a family tree structure. Print out the tree to the screen. Threading Create A Progress Bar for Downloads - Create a progress bar for applications that can keep track of a download in progress. The progress bar will be on a separate thread and will communicate with the main thread using delegates. Bulk Thumbnail Creator - Picture processing can take a bit of time for some transformations. Especially if the image is large. Create an image program that can take hundreds of images and converts them to a specified size in the background thread while you do other things. For added complexity, have one thread handling re-sizing, have another bulk renaming of thumbnails, etc. Web Page Scraper - Create an application that connects to a site and pulls out all links, or images, and saves them to a list. Optional: Organize the indexed content and don’t allow duplicates. Have it put the results into an easily searchable index file. Online White Board - Create an application that allows you to draw pictures, write notes and use various colors to flesh out ideas for projects. Optional: Add a feature to invite friends to collaborate on a whiteboard online. Get Atomic Time from Internet Clock - This program will get the true atomic time from an atomic time clock on the Internet. Use any one of the atomic clocks returned by a simple Google search. Fetch Current Weather - Get the current weather for a given zip/postal code. Optional: Try locating the user automatically. Scheduled Auto Login and Action - Make an application that logs into a given site on a schedule and invokes a certain action and then logs out. This can be useful for checking webmail, posting regular content, or getting info for other applications and saving it to your computer. E-Card Generator - Make a site that allows people to generate their own little e-cards and send them to other people. Do not use Flash. Use a picture library and perhaps insightful mottos or quotes. Content Management System - Create a content management system (CMS) like Joomla, Drupal, PHP Nuke, etc. Start small. Optional: Allow for the addition of modules/addons. Web Board (Forum) - Create a forum for you and your buddies to post, administer and share thoughts and ideas. CAPTCHA Maker - Ever see those images with letters numbers when you signup for a service and then ask you to enter what you see? It keeps web bots from automatically signing up and spamming. Try creating one yourself for online forms. Files Quiz Maker - Make an application that takes various questions from a file, picked randomly, and puts together a quiz for students. Each quiz can be different and then reads a key to grade the quizzes. Sort Excel/CSV File Utility - Reads a file of records, sorts them, and then writes them back to the file. Allow the user to choose various sort style and sorting based on a particular field. Create Zip File Maker - The user enters various files from different directories and the program zips them up into a zip file. Optional: Apply actual compression to the files. Start with Huffman Algorithm. PDF Generator - An application that can read in a text file, HTML file, or some other file and generates a PDF file out of it. Great for a web-based service where the user uploads the file and the program returns a PDF of the file. Optional: Deploy on GAE or Heroku if possible. Mp3 Tagger - Modify and add ID3v1 tags to MP3 files. See if you can also add in the album art into the MP3 file’s header as well as other ID3v2 tags. Code Snippet Manager - Another utility program that allows coders to put in functions, classes, or other tidbits to save for use later. Organized by the type of snippet or language the coder can quickly lookup code. Optional: For extra practice try adding syntax highlighting based on the language. Databases SQL Query Analyzer - A utility application in which a user can enter a query and have it run against a local database and look for ways to make it more efficient. Remote SQL Tool - A utility that can execute queries on remote servers from your local computer across the Internet. It should take in a remote host, user name, and password, run the query and return the results. Report Generator - Create a utility that generates a report based on some tables in a database. Generates sales reports based on the order/order details tables or sums up the day's current database activity. Event Scheduler and Calendar - Make an application that allows the user to enter a date and time of an event, event notes, and then schedule those events on a calendar. The user can then browse the calendar or search the calendar for specific events. Optional: Allow the application to create re-occurrence events that reoccur every day, week, month, year, etc. Budget Tracker - Write an application that keeps track of a household’s budget. The user can add expenses, income, and recurring costs to find out how much they are saving or losing over a period of time. Optional: Allow the user to specify a date range and see the net flow of money in and out of the house budget for that time period. TV Show Tracker - Got a favorite show you don’t want to miss? Don’t have a PVR or want to be able to find the show to then PVR it later? Make an application that can search various online TV Guide sites, locate the shows/times/channels and add them to a database application. The database/website then can send you email reminders that a show is about to start and which channel it will be on. Travel Planner System - Make a system that allows users to put together their own little travel itinerary and keep track of the airline/hotel arrangements, points of interest, budget, and schedule. Graphics and Multimedia Slide Show - Make an application that shows various pictures in a slide show format. Optional: Try adding various effects like fade in/out, star wipe, and window blinds transitions. Stream Video from Online - Try to create your own online streaming video player. Mp3 Player - A simple program for playing your favorite music files. Add features you think are missing from your favorite music player. Watermarking Application - Have some pictures you want copyright protected? Add your own logo or text lightly across the background so that no one can simply steal your graphics off your site. Make a program that will add this watermark to the picture. Optional: Use threading to process multiple images simultaneously. Turtle Graphics - This is a common project where you create a floor of 20 x 20 squares. Using various commands you tell a turtle to draw a line on the floor. You have moved forward, left or right, lift or drop the pen, etc. Do a search online for "Turtle Graphics" for more information. Optional: Allow the program to read in the list of commands from a file. GIF Creator A program that puts together multiple images (PNGs, JPGs, TIFFs) to make a smooth GIF that can be exported. Optional: Make the program convert small video files to GIFs as well. Security Caesar cipher - Implement a Caesar cipher, both encoding, and decoding. The key is an integer from 1 to 25. This cipher rotates the letters of the alphabet (A to Z). The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A). So key 2 encrypts "HI" to "JK", but key 20 encrypts "HI" to "BC". This simple "monoalphabetic substitution cipher" provides almost no security, because an attacker who has the encoded message can either use frequency analysis to guess the key, or just try all 25 keys.

Decentralized Finance & It's use cases- DeFi (Decentralized Finance) Another open-world approach to the current financial system. Products that allow you to borrow, save, invest, trade, and more. Based on open source technology anyone can plan with. DeFi is an open and global financial system that has been built for years - another way of being a sharp, tightly managed, and cohesive system of decades-old infrastructure and processes. It gives you more control and visibility than your money. It gives you exposure to global markets and other options for your local currency or banking options. DeFi products open financial services to anyone with an internet connection and are highly managed and maintained by their users. To date, tens of billions of dollars worth of crypto have gone through DeFi applications and is growing every day. What is DeFi? DeFi is an integrated name for financial products and services accessible to anyone who can use Ethereum - anyone with an Internet connection. With DeFi, markets remain open and no central authorities can block payments or deny you access to anything. Services that used to be slow and vulnerable to human error are now automated and secure as they are governed by a code that anyone can check and evaluate. There is a thriving crypto-economy out there, where you can borrow, borrow, length / short, earn interest, and more. Crypto-savvy Argentinians have used DeFi to escape inflation. Companies have begun distributing their pay to their employees in real-time. Some people even withdraw and repay loans worth millions of dollars without the need for personal information. DeFi vs Traditional Finance One of the best ways to see the power of DeFi is to understand the problems that exist today. Some people are not given access to setting up a bank account or using financial services. Lack of access to financial services can prevent people from being employed. Financial services can prevent you from paying. Hidden payment for financial services is your data. Governments and private institutions can close markets at will. Trading hours are usually limited to one-hour business hours. Transfers may take days due to personal processes. There is a premium for financial services because mediation institutions require their cutting. DeFi Use Cases DeFi has revolutionized the financial world over the past few years. This new approach to financial planning can transcend asset systems through efficiency and security. It is true that there are certain dangers in DeFi but those are within the concrete limits. Let's take a look at the most effective DeFi usage cases - Asset Management One of DeFi's biggest effects is that users can now enjoy more control over their assets. Many DeFi projects provide solutions that allow users to manage their assets, including - buying, selling, and transferring digital assets. Therefore, users can also earn interest on their digital assets. Contrary to the traditional financial system, DeFi allows users to maintain the privacy of their sensitive information. Think of the secret keys or passwords of your financial accounts - you should have shared that information with the appropriate organizations beforehand. Now, different DeFi projects, such as Metamask, Argent, or Gnosis Safe help users encrypt and store those pieces of information on their devices. This ensures that only users have access to their accounts and can manage their assets. Therefore, asset management is one of the most widely used financial services cases for users. Compliance with AML and CFT Rates through the KYT Mechanism Traditional financial systems focus heavily on Know-Your-Customer (KYC) agreements. KYC Guidelines are its major law enforcement tool for using Anti-Money Laundering (AML) and Countering-the-Financing-of-Terrorism (CFT) standards. However, KYC guidelines often conflict with DeFi's privacy efforts. DeFi responds to this problem with a new concept called the Know-Your-Transaction (KYT) mechanism. This approach suggests that low-level infrastructure will focus on ethical behavior for digital addresses rather than user considerations. Therefore, KYT solves two issues simultaneously - monitoring real-time operations and ensuring user privacy. This makes KYT one of the biggest gaps in low-cost cases. Non-Governmental Organizations or DAOs The DAOs are partners of the central financial institutions of DeFi - making it one of the pillars of low-income finance cases. In the traditional system, central financial institutions play a major role. These organizations operate as administrative institutions that regulate basic financial operations, such as monetization, asset management, administrative utilization, etc. The Ethereum blockchain echerestem has introduced empowered organizations to achieve the same goals. However, DAOs are naturally empowered and do not conform to the limits set by central governments or authorities. Analysis and Risk Tools Transparency and redistribution of world power have opened the way for the discovery and analysis of unprecedented user data. With access to this information, users can make informed business decisions, discover new financial opportunities, and implement better risk management strategies. A new type of data analytics with useful blockchain tools and dashboards has emerged in this industry trend. DeFi projects such as DeFi Pulse or CoDeFi Data bring an impressive amount of analytics and risk management tool. Now, businesses are moving faster as they enjoy unpredictable competitive advantages. This is certainly one of the most widely used financial cases. Receivables and Manufacturing Goods Smart contracts allow for the receipt of token receipts and have become one of the most distinctive scenarios for DeFi use. Making a token further means setting a contract value based on the underlying financial asset or set of assets. This underlying financial asset acts as a security measure, which means it can include - bonds, fiat currencies, commodities, market indicators, interest rates, or stock prices. Now, the issuance of outgoing tokens is a secondary security and their value varies with the number of key securities (bonds or fiat money). Thus, the output actually creates artificial goods. Synthetix and dYdX are some of the leading DeFi projects focused on token acquisitions. Network Infrastructure Effect In a DeFi ecosystem, objects within the system can connect and interact. This design feature is known as integration and serves as a protocol for infrastructure development. As a result, DeFi projects are continuously integrated with the network result. Infrastructure tools for use of DeFi applications are remarkable. Various DeFi projects, such as TruffleSuite or InfuraAPI, are good examples in this case. Enhanced Digital ID Blockchain-based identity system systems are already gaining a lot of attention in recent times. Pairing DeFi programs with these patent systems can help people access the global economic system. The traditional method rewards personal income or assets collected as credit providers. With digital identity paired with DeFi, you may be looking for other practical attributes, such as - financial services or professional ability. This new type of digital ID can help the poor to access DeFi apps from any internet connection. It can certainly be one of the cases of possible use. Insurance Insurance is one of the largest financial institutions and has already been proven to be one of the biggest charges for using DeFi. The current insurance system is crowded with paperwork, old audit plans, and bureaucratic insurance claim processes. With the successful implementation of smart contracts, all these problems with the current system can be solved. Many DeFi projects (Nexus Mutual, Opyn, and VouchForMe) provide blockchain access to insurance against DeFi or contract risk. P2P borrowing and borrowing As DeFi bids farewell to traditional banking systems, a space for the lending and lending market has emerged. Therefore, borrowing and lending is one of the most important aspects of using DeFi. However, the DeFi ecosystem is well suited for peer-to-peer (P2P) borrowing and lending efforts. Many DeFi projects have already entered the market focusing on this particular application case. Among these programs, Compound and PoolTogether are two well-known names. These projects have independent policies for lending and lending. Payment Solutions One of DeFi's top drivers was serving non-bankers or understated banks from the get-go. DeFi's natural features make it ideal for solving the problems of current global payment systems. DeFi provides fast, secure, and transparent solutions compared to asset systems. As DeFi lowers the demand for intermediaries, making payments easier and more transparent, DeFi-based blockchain-based payment solutions can appeal to non-bankers.

This project is an Orders and Notifications Management system designed to handle various aspects of product orders, customer accounts, and notifications. The system provides features such as product listing, customer account creation, order placement (both simple and compound), order details, shipping, and notification management.

Dynamic compound formation website empowering users to choose construction materials effortlessly. Robust admin features facilitate seamless product management and vendor collaboration, with the added convenience of cash-on-delivery.

A Claude Code skill toolkit that compounds over time — write clearly, learn from sessions, coach yourself toward better prompts.

RESTful API for Orders & Notifications Management. Features: Product listing, user account creation, order placement (simple & compound), shipping, notification creation, and a dynamic notifications queue. Bonus: Automated order cancellation, live stats on sent notifications. Built for effective e-commerce and user communication.

This project is an Orders and Notifications Management system designed to handle various aspects of product orders, customer accounts, and notifications. The system provides features such as product listing, customer account creation, order placement (both simple and compound), order details, shipping, and notification management.

The Product List with Cart app lets users manage their cart, view a confirmation modal, and reset orders. Created using Styled Components, React Compound Components, React Portal, and Context API for state management

"Agro pharma" refers to a company or industry that develops and manufactures pharmaceutical products derived from agricultural sources, essentially using plant-based compounds to create medications, often focusing on pest and disease management in crops.