Transactions Program

This program reads in a CSV file of transactions and spends the given number of points, following the rules outlined in the prompt. It then prints out the remaining point balances for each payer.

Requirements

• Java Language
• provided .CSV file

Usage

To run the program, open a terminal and navigate to the directory where the transactions.java file is located. Then run the following command:

java transactions <filename.csv>

Replace <points> with the number of points to spend, and <filename.csv> with the name of the CSV file to read.

CSV Format

The CSV file should have the following format:

payer, points, timestamp
DANNON, 1000, 2020-11-02T14:00:00Z
UNILEVER, 200, 2020-10-31T11:00:00Z
DANNON, -200, 2020-10-31T15:00:00Z
MILLER COORS, 10000, 2020-11-01T14:00:00Z
DANNON, 300, 2020-10-31T10:00:00Z

Each row should represent a transaction, with the payer name, the number of points (positive or negative), and the timestamp in ISO 8601 format. The header row should be omitted.

Output

The program will print out the remaining point balances for each payer in the following format:

  {"MILLER COORS"=5300, "UNILEVER"=0, "DANNON"=1000}

This indicates that DANNON has 1000 points remaining, while UNILEVER and MILLER COORS have 0 points remaining.

Implementation

The program uses a Map to keep track of the point balances for each payer, and a List to store the transaction information. The program first reads in the CSV file and populates these data structures, then sorts the transactions by timestamp and spends the given number of points according to the rules outlined in the prompt. Finally, the program prints out the remaining point balances for each payer.