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Introduction to Computer Science

Computer Science Department

Heart Transplant – 80 course points

This assignment consists of creating an abstract data type called HeartTransplant, where you will match available donor hearts to recipients waiting for transplant.

Refer to our Programming Assignments FAQ for instructions on how to install Visual Studio Code, how to use the command line and how to submit your assignments.

Programming

We provide this ZIP FILE containing HeartTransplant.java. Update and submit the file on Autolab.

Observe the following rules:

  1. DO NOT use System.exit().
  2. DO NOT add the project or package statements.
  3. DO NOT change the class name.
  4. DO NOT change the headers of ANY of the given methods.
  5. DO NOT add any new class fields.
  6. You may USE any of the libraries provided in the zip file.

Overview

A heart transplant is a surgical procedure that replaces the person’s heart with a donor heart. A person may require a heart transplant for several reasons including congenital, arterial and muscle diseases or for unforeseen reasons such as accidents or viral infections.

The donor heart is matched to the recipient by blood type. Additional variables are also used to decide which recipient receives a heart if there are not enough hearts available for all recipients waiting for a transplant. The variables included in the decision may include the recipient state of health, cause of the heart condition and the urgency of the transplant.

The primary goal of this project is for you to write a HeartTransplant class that has the ability to select the patient, from a pool of patients, with the highest potential to survive the longest after the heart transplant surgery. Used the HeartTransplantDriver to test the methods within the HeartTransplant class.

Files Provided

  • HeartTransplantDriver.java
    • This is the program you should compile and run.
    • It builds a HeartTransplant object and calls instance methods on it.
    • No need to make changes to it, but you are welcome to change it if you want. It is for testing purposes only.
  • SurvivabilityByAge.java
    • Stores information about the survivability of patients, by age, after n years post heart transplant surgery.
  • SurvivabilityByCause.java
    • Stores information about the survivability of patients, by heart condition cause, after n years post heart transplant surgery.
  • Patient.java
    • Stores patient information.
    • Contain constants representing patient codes (health condition code, gender code, urgency code, ethnicity code…)
  • Data.txt
    • Contains patient information, as well as survivability by age and cause rates.
    • This file should be piped when executing HeartTransplantDriver
    • How to run the driver: 
      • Compile: javac HeartTransplantDriver.java
      • Execute: java HeartTransplantDriver < data.txt
  • HeartTransplant.java
    • This is the file you will write your code on.
    • Provided as an empty file, complete it based on documentation.

Understanding the Driver:

  1. The HeartTransplantDriver will create an HeartTransplant object using its default constructor. 
  2. The driver will then initialize the three instance variables in the object using the following instance methods:
    1. readPatients(int numberOfLines)
    2. readSurvivabilityByAge(int numberOfLines) 
    3. readSurvivabilityByCause(int numberOfLines)
  3. Finally, the driver will test the three instance methods on the object:
    1. getPatientsWithAgeAbove(int age)
    2. getPatientsByUrgency( int urgency)
    3. getPatientForTransplant()

How to use the SurvivabilityByAge, SurvivabilityByCause, and Patient classes:

SurvivabilityByAge

  • Constructor: default
  • addData(int age, int year, double rate)
    • add the survivability rate relating to age and number of years post transplant to the object can be accessed by using getData() method in the future.
  • getRate(int age, int year)
    • Returns the survivability rate given patient age and years post transplant.
      • If not found, returns -1
  • getDataSize()
    • Returns an integer representing the number of data points currently stored in the object.
  • printAllData()
    • prints out all data points.
  • toString(int a, int y) 
    • Returns the string representation of the survivability at a age after y years.
    • returns “NF” if not found 

SurvivabilityByCause

  • Constructor: default
  • addData(int cause, int year, double rate)
    • add the survivability rate relating to cause and number of years after the transplant to the object can be accessed by using getData() method in the future.
  • getRate(int cause, int year)
    • Returns the survivability rate given heart disease cause and years post transplant.
    • If not found, returns -1.
  • getDataSize()
    • Returns an integer representing the number of data points currently stored in the object.
  • printAllData()
    • prints out all data points.
  • toString(int cause, int year)
    • Returns the string representation of the survivability with cause after y years.
    • returns “NF” if not found

Patient  (Please read the java file)

  • Stores 19 public constants describing the meaning of all the codes from the input file Data.txt; details in Patients.java
  • Instance variables (all private, can be only accessed by getter methods):
    •     int id;            
      • unique identification of the patient
    •     int ethnicity;      
      • An integer between [10, 12] representing the ethnicity of the patient 
    •     int gender;
      • An integer between [13, 15] representing the gender of the patient
    •     int age;
      • An integer representing the age of the patient
    •     int cause;
      • An integer between [0, 4] representing the cause of the condition
    •     int stateOfHealth
      •  An integer between [5, 7] representing the current state of health
    •     int urgency;
      •  An integer between [8, 9] represents the patient’s urgency, a higher integer meaning more urgent.
    • boolean needHeart; 
      •  boolean representing if the patient is still waiting for a heart fo transplant; if true, the patient is still waiting for a heart transplant; if false, the patient no longer needs a heart, the patient already had surgery.
    • Constructor: Patient (int id, int ethnicity, int gender, int age, int cause, int urgency, int stateOfHealth)
      • needHeart is default to true, other values are initialized to the data passed in
  • Instance Methods
    • int getAge()
      • Returns the Patient’s age
    • int getEthnicity()
      • Returns the Patient’s ethinicity
    • int getGender()
      • Returns the Patient’s gender
    • int getCause()
      • Returns the Patient’s cause for the heart condition
    • int getUrgency()
      • Returns the Patient’s urgency for the transplant
    • int getStateOfHealth()
      • Returns the Patient’s state of health
    • boolean getNeedHeart()
      • Returns boolean for if the Patient is still waiting for a heart
    • Void setNeedHeart(boolean needHeart)
      • Set needHeart’s status
    • boolean equals (Object other)
      • returns true if the current object stores the same value as other
    • String toString()
      • Returns the string representation of the Patient

Detailed description for HeartTransplant.java:

***the name of the methods/instance variables MUST match with the description***

(Side note: this might seem like a lot of work, but all the methods are really short, and some methods even share the same logic, meaning the general structure for one method can be the same for multiple methods, so DON’T PANIC, you have got this)

Instance variables (more details in their respective java files)

  • patients: an array of Patient objects
  • survivabilityByAge: a SurvivabilityByAge object
  • survivabilityByCause: a SurvivabilityByCause object 

Constructors:

  • HeartTransplant()
    • Default constructor.
    • Initializes patients to null.
    • Initializes survivabilityByAge to null.
    • Initializes survivabilityByCause to null.

Instance Methods:

  • getPatients ()
    • Description: 
      • returns the instance variables – patients 
    • Return type:
      • array of Patient objects
  • getSurvivabilityByAge()
    • Description: 
      • returns the instance variables – survivabilityByAge
    • Return type: 
      • a SurvivabilityByAge object
  • getSurvivabilityByCause ()
    • Description: 
      • returns the instance variables – survivabilityByCause
    • Return type: 
      • a SurvivabilityByCause object
  • readPatients (int numberOfLines)
    • Description: 
      • Initialize the instance variable patients with an array of patient objects with the size of numberOfLines. The information needed to create the patient objects are read from a data file using the StdIn library. The data file will be redirected to the program HearTransplantDriver when executed.
    • Return type:
      • void
    • Data format:
      • Each line refers to one Patient; each line has the format of (all are integers): ID Ethnicity Gender Age Cause Urgency StateOfHealth
  • readSurvivabilityByAge (int numberOfLines)
    • Description: 
      • Initialize the instance variable survivabilityByAge with a SurvivabilityByAge object 
      • Then make multiple calls on survivabilityByAge.addData(int age, int year, double rate); to add data to survivabilityByAge
    • Return type:
      • void
    • Data format:
      • Each line refers to one set of data, each line has the format of (age and yearsPostTransplant are integers, rate will be in double): age yearsPostTransplant rate.
  • readSurvivabilityByCause (int numberOfLines)
    • Description: 
      • Initialize the instance variable survivabilityByCause with a SurvivabilityByCause object 
      • Then make multiple calls on survivabilityByCause.addData(int cause, int year, double rate); to add data to survivabilityByCause 
      • The meaning of the integer cause can be found in Patient.java
    • Return type:
      • void
    • Data format:
      • Each line refers to one set of data; each line has the format of (cause and yearsPostTransplant are integers, the rate will be in double): cause yearsPostTransplant rate cause yearsPostTransplant rate
  • getPatientsWithAgeAbove (int maxAge)
    • Description: 
      • Find all patient objects with age greater or equal to maxAge in the instance variable patients, and return them as an array with that exact size.
      • For example, assume patients currently stores 10 people with the age of {1,2,3,4,5,6,7,8,9,10}, if getPatientsWithAgeAbove(5) is called, then it should returns a size 6 array with the 6 patient objects with age greater or equal to 5.
    • Return type:
      • Array of Patient objects
  • getPatientsByUrgency (int urgency)
    • Description: 
      • Find all patient objects with the targeted urgency in the instance variable patients, and return them as an array with that exact size.
    • Return type:
      • Array of Patient objects
  • getPatientsByHeartConditionCause (int cause)
    • Description: 
      • Find all patient objects that have the cause of condition equals to the input parameter cause, and return them as an array with that exact size.
    • Return type:
      • Array of Patient objects
  • getPatientForTransplant ()
    • Description: 
      • Among all patients who need a heart and with the highest urgency, find the patient with the highest survivability rate in five years. Then the target patient‘s needHeart should be marked as false and return the patient object.
      • This survivability rate is calculated by finding the average of SurvivabilityByAge and SurvivabilityByCause. 
      • You can get the survivability by calling on non-static methods getRate(int age, int year) and getRate(int cause, int year) in SurvivabilityByAge and SurvivabilityByCause
      • Because the method marks the target patient’s needHeart to false, repetitive calls on this method n times will give the top n patients with the highest survivability rate.
    • Return type:
      • A Patient object

Data File and Execution

We provide a data file with real data that is the input for the program. The data file contains information on 21 people of the same blood type, 24 survivability by age rates, and 15 survivability by heart condition cause rates. More on the data file format below.

Compile the program as follows:

  • javac HeartTransplantDriver

Execute the program as follows:

  • java HeartTransplantDriver < data.txt

The file data.txt is redirected as the input for the program HeartTransplantDriver and can be read using the StdIn library functions StdIn.readInt() and StdIn.readDouble().

Data File Format

The data file is divided in three sections. The first section is the person section, the second the rates of survivability by age section, and the third is the rates of survivability by heart condition cause section.

First section: person

  • The first line of this section has an integer that refers to the number of persons in the file. The file has one person per line in the following format:
  • PersonID Ethinicity Gender Age Cause Urgency StateOfHealth
  •  
  • The example below has 3 persons, the first person’s ID  4101, Ethnicity 10, Gender 13, Age 75, Cause 3, Urgency 8, and StateOfHealth 7. You can see the meaning of each code in the Person.java file.

Second section: survivability by age

  • The first line of this section has an integer that refers to the number of survivability by age rates in the file. The file has one rate per line in the following format:
  • Age YearsPostTransplant Rate
     
  • The example below has 8 rates, the first rate specifies that people with age LESS than 1 year old, 5 years post transplant have a survivability rate of 83.6%.

Third section: survivability by heart condition cause

  • The first line of this section has an integer that refers to the number of survivability by cause rates in the file. The file has one rate per line in the following format:
  • Cause YearsPostTransplant Rate
     
  • The example below has 5 rates, the first rate specifies that people with heart condition cause 4 (heart muscle disease), 1 year post transplant have a survivability rate of 89.4%.You can see the meaning of each code in the Person.java file.
3
4101  10  13  75  3  8  7
4102  11  14  78  4  9  5
4103  12  14  40  3  8  5
8
 1  5 83.6
 6  5 87.4
 11 5 86.8
 18 5 90
 35 5 86.9
 50 5 88.8
 65 5 87.8
120 5 84.3
5
4 1 89.4
1 1 82.1
3 1 87.1
0 1 88.2
2 1 88.2

Before submission

  1. Collaboration policy. Read our collaboration policy here.
  2. Update @author. Update the @author tag of the files with your name, email and netid.
  3. Submitting the assignment. Submit HeartTransplant.java via the web submission system called Autolab. To do this, click the Assignments link from the course website; click the Submit link for that assignment.

Getting help

If anything is unclear, don’t hesitate to drop by office hours or post a question on Piazza. Find instructors office hours by clicking the Staff  link from the course website.
In addition to office hours we have the CAVE (Collaborative Academic Versatile Environment), a community space staffed with lab assistants which are undergraduate students further along the CS major to answer questions.

Assignment by Haolin (Daniel) Lin and Ana Paula Centeno