ShareSpend

A bill-splitting application to track shared expenses in a group, developed with Node and React.

Explanation of Transaction Minimisation Algorithm

We implemented a greedy algorithm to minimise the number of transactions required to settle the debts between all members of a group. The algorithm runs in O(n log n), where n is the number of users – this means that it scales well with the number of users.

A simple example of this algorithm . In this example, Alice owes Bob ₹10 and Bob owes Charlie ₹10 for a total of two transactions. The algorithm will suggest that Alice pays Charlie ₹10 directly, meaning only one transaction is required to settle the debts.

Screenshots

Installation and Usage

Setting up the MongoDB Database

1. Create a file in the server directory with the name: .env
2. Open the file in a text editor (such as Notepad or TextEdit).
3. Add the following line to the file, replacing <uri> with the URI of your MongoDB database:

MONGODB_URI="<uri>"

4. Save the file.

Running the Server

1. Open a terminal window.
2. Ensure that you're in the root directory: sharepend
3. Navigate to the server directory: cd server
4. Install dependencies: npm install
5. Run the server: node app

Running the Client

1. Open a new terminal window (separate to the previous one).
2. Ensure that you're in the root directory: sharepend
3. Navigate to the server directory: cd client
4. Install dependencies: npm install
5. Run the client: npm start
6. Browse to the URL provided in the terminal window.