CMPE223/242 - Programming Homework 4

This repository contains the solution to Programming Homework 4 for the CMPE223/242 course, Spring 2024. The assignment focuses on efficient data structure implementations using heap-based priority queues for two different tasks.

Overview

Task 1: Median Age Calculation

In this task, we implement an efficient algorithm to calculate the median age of users dynamically for the Exxen streaming platform. We use two heaps:

• Max-Heap: Stores the smaller half of the ages.
• Min-Heap: Stores the larger half of the ages.

The algorithm ensures efficient insertion and retrieval of the median after each new user signs up.

Example Usage

MedianOfAges medianOfAges = new MedianOfAges();
medianOfAges.insertNum(22);
medianOfAges.insertNum(35);
System.out.println("The recommended content will be for ages under: " + medianOfAges.findMedian());

medianOfAges.insertNum(30);
System.out.println("The recommended content will be for ages under: " + medianOfAges.findMedian());

medianOfAges.insertNum(25);
System.out.println("The recommended content will be for ages under: " + medianOfAges.findMedian());

Example Output

The recommended content will be for ages under: 28.5
The recommended content will be for ages under: 30.0
The recommended content will be for ages under: 27.5

Task 2: Priority-Based Task Scheduling

In this task, we create a heap-based priority queue to manage task scheduling based on deadlines and durations, simulating a real-world logistics problem. The system handles task execution based on priority and advances the internal time variable accordingly.

Example Input (sampleinput1.txt)

schedule shipmentA 1300 30
schedule shipmentB 7200 2300
schedule shipmentC 2359 300
run 2400

Example Output

0: adding shipmentA with deadline 1300 and duration 30
0: adding shipmentB with deadline 7200 and duration 2300
0: adding shipmentC with deadline 2359 and duration 300
0: busy with shipmentA with deadline 1300 and duration 30
30: done with shipmentA
30: busy with shipmentC with deadline 2359 and duration 300
330: done with shipmentC
330: busy with shipmentB with deadline 7200 and duration 2300
2400: adding shipmentB with deadline 7200 and duration 230

Project Structure

• Shipment.java: Defines the Shipment object with properties such as name, deadline, and duration. It also includes an overridden toString() method for printing shipment details.
• ShipmentComparator.java: Implements the Comparator<Shipment> interface to compare and sort shipments based on their deadlines.
• ShipmentTracking.java: Manages the shipment process with methods such as scheduleShipment(), startShipment(), completeShipment(), and runTime().
• TXTReader.java: Reads input files and processes the shipment tasks accordingly.
• Task2Tester.java: A tester class that uses TXTReader to load and test different input files such as sampleinput1.txt and sampleinput2.txt.
• sampleinput1.txt: A sample input file used for testing the task scheduling system.
• README.md: Project documentation.

How to Run

1. Clone the repository:

   git clone https://github.com/ewredewir/algorithm101-homework.git

2. Compile all the Java files:

   javac Shipment.java ShipmentComparator.java ShipmentTracking.java TXTReader.java Task2Tester.java

3. Run Task 2 with the sample input:

   java Task2Tester

By default, the Task2Tester.java uses the sampleinput1.txt file, but you can test other inputs by creating new .txt files and providing their paths to the TXTReader as shown:

TXTReader txtReader = new TXTReader();
txtReader.readTxtFile(new File("your_input_file.txt"));

Features

• Dynamic Median Calculation: Efficient median age retrieval using two heaps for dynamic user data.
• Priority-Based Task Scheduling: Simulated logistics scheduling using custom heap-based priority queues.

License

This project is for educational purposes and is licensed under the MIT License. See the LICENSE file for details.