hospitalsysuos.java

国外的数据结构与算法分析用书

package hospital_sys;

import java.io.*;
import dslib.file.*;
import dslib.dictionary.PKeyedDictUos;
import dslib.base.*;

/**	This class provides a simple hospital system that maintains information 
	about patients */
public class HospitalSysUos
{
	final int MENU_EXIT = 9;
	
	/**	File storing each patient by his/her specified hospitalization number. */
	PKeyedDictUos patNumToPatFile;

	/*	The following files are inverted lists that provide access to the hospitlization 
		numbers of patients by doctor's name, drug name, patient name, and bed number. */

	/**	File storing the hospitalization numbers of patients for each doctor's name. 
		Note that a doctor can have many patients */
	PKeyedDictUos doctorToPatNumFile;
	
	/**	File storing the hospitalization numbers of patients using each drug. 
		Note that many people can take the same drug */
	PKeyedDictUos drugToPatNumFile;
	
	/**	File storing with each patient's name, his/her hospitalization number. 
		Assume that no two people have the same name (first and last) */
	PKeyedDictUos patNameToPatNumFile;

	/**	File storing the hospitalization number of the patient in each bed */
		PKeyedDictUos bedToPatNumFile;
		
		BufferedReader input;
		
		/**	Initialize and run the system. <br>
			Analysis: Time = O(numbers of the queries * time for each query) */
		public HospitalSysUos()
		{
			System.out.println("\nWelcome to the hospital system\nInitially the system is empty.\n");
			patNumToPatFile = new BtreeFileUos(4,"./hospital_sys/patient_data_file", "./hospital_sys/patient_node_file", 1000, 2000);
			
			doctorToPatNumFile = new BtreeFileUos(4, "./hospital_sys/doctor_data_file", "./hospital_sys/doctor_node_file", 1000, 2000);
			
			drugToPatNumFile = new BtreeFileUos(4, "./hospital_sys/drug_data_file", "./hospital_sys/drug_node_file", 1000, 2000);
			
	
			patNameToPatNumFile = new BtreeFileUos(4, "./hospital_sys/name_data_file", "./hospital_sys/name_node_file", 1000, 2000);
			
			bedToPatNumFile = new BtreeFileUos(4, "./hospital_sys/bed_data_file", "./hospital_sys/bed_node_file", 1000, 2000);
			
			input = new BufferedReader(new InputStreamReader(System.in));
			run();
		}
		
		/**	Run the system. <br>
			Analysis: Time = O(numbers of the queries * time for each query) */
		public void run()
		{
			int response =0;
			while (response != MENU_EXIT)
			{
				response = menuQuery();
				switch(response)
				{
					case 1: 
						addAPatient();
						break;
					case 2:
						deleteAPatient();
						break;
					case 3: 
						outputPatientList();
						break;
					case 4:
						searchByPatName();
						break;
					case 5:
						searchByDocName();
						break;
					case 6:
						searchByDrug();
						break;
					case 7:
						searchByBed();
						break;
					case 8:
						searchByHospNum();
						break;
					case 9:
						exitSys();
						break;
					default:
						System.out.println("Invalid choice input");
						break;
				}
			}
		}

	/**	Display the main menu and return user's choice. <br>
		Analysis: Time = O(1) */
	public int menuQuery()
	{
		boolean validChoice = false;
		int result = -1;
		while (!validChoice)
		{
			System.out.println("\nMAIN MENU");
			System.out.println("---------");
			System.out.println("1. Add a patient");
			System.out.println("2. Delete a patient");
			System.out.println("3. View all patient records");
			System.out.println("4. Search for patient by patient's name");
			System.out.println("5. Search for patient(s) by doctor's name");
			System.out.println("6. Search for patient(s) by drug");
			System.out.println("7. Search for patient by bed number");
			System.out.println("8. Search for patient by hospitalization number");
			System.out.println("9. Exit system");
			System.out.print("\nChoice : ");
			try
			{
				result = Integer.parseInt(input.readLine());
			}catch (Exception e)
			{
				System.out.println("Invalid input in menuQuery()");
				result = -1;
			}
			validChoice = (result >=1) && (result <= MENU_EXIT);
		}
		return result;
	}
	
	/**	Create a patient from user data and insert it into the 
		index file and update the inverted lists. <br> 
		Analysis: Time = O(has()) + O(insert()) for each of the files:
		patNumToPatFile, bedToPatNumFile, doctorToPatNumFile, and
		drugToPatNumFile. */
	public void addAPatient()
	{
		PatientUos newPatient = null;
		try{
			System.out.print("Patient's name : ");
			String name = input.readLine();
			System.out.print("Patient's doctor : ");
			String doc = input.readLine(); 
			System.out.print("Drug : ");
			String drug = input.readLine();
			System.out.print("Hospitalization number : ");
			int hn = Integer.parseInt(input.readLine());
			System.out.print("Bed number : ");
			int bn = Integer.parseInt(input.readLine());
			newPatient = new PatientUos(name, bn, doc, drug, hn);
		}catch (Exception e)
		{
			System.out.println("Valid input in addPatient()");
			return;
		}
	
		/**	Create new record and add to the files */
		int hosp = newPatient.hospNum();
		int bed = newPatient.bedNum();
		if (patNumToPatFile.has(new Integer(hosp)))
			System.out.println("Can not insert the new patient as the hospitilization number is already in use"); 
		else if (bedToPatNumFile.has(new Integer(bed)))
			System.out.println("Can not insert the new patient as the bed number is already in use");
		else if (patNameToPatNumFile.has(newPatient.name))
			System.out.println("Can not insert the new patient as another patient has the name");
		else
		{
			patNumToPatFile.insert(new Integer(hosp), newPatient);
			patNameToPatNumFile.insert(newPatient.name(), new Integer(hosp));
			bedToPatNumFile.insert(new Integer(bed), new Integer(hosp));
			
			/*	As the doctor-hosp number file is a PKeyedDictUos, each entry must have
				a unique key.  Use the (doctor, hosp number) pair as the key and a null item.
				Store (doctor, -1) as the first pair for each doctor. */
			String doc = newPatient.docName();
			ComparablePairUos docPatPair = new ComparablePairUos(doc, new Integer(-1));
			if (doctorToPatNumFile.has(docPatPair))
			{
				docPatPair = new ComparablePairUos(doc, new Integer(hosp));
				doctorToPatNumFile.insert(docPatPair, null);
			}
			else
			{
				doctorToPatNumFile.insert(docPatPair, null);
				docPatPair = new ComparablePairUos(doc, new Integer(hosp));
				doctorToPatNumFile.insert(docPatPair, null);
			}
	
			/*	As the drug-hosp number file is a PKeyedDictUos, each entry must have
				a unique key.  Use the (durg, hosp number) pair as the key and a null item.
				Store (drug, -1) as the first pair for each drug. */
			String drug = newPatient.drugName();
			ComparablePairUos drugPatPair = new ComparablePairUos(drug, new Integer(-1));
			if (drugToPatNumFile.has(drugPatPair))
			{	
				drugPatPair = new ComparablePairUos(drug, new Integer(hosp));
				drugToPatNumFile.insert(drugPatPair, null);
			}
			else
			{	
				drugToPatNumFile.insert(drugPatPair, null);
				drugPatPair = new ComparablePairUos(drug, new Integer(hosp));
				drugToPatNumFile.insert(drugPatPair, null);
			}
		} 
	}

	/**	Delete a user specified patient by hospitalization number. <br>
		Analysis: Time = O(search()) + O(deleteItem()) for each of the files:
		patNumToPatFile, doctorToPatNumFile, drugToPatNumFile,
		patNameToPatNumFile, and bedToPatNumFile. */
	public void deleteAPatient()
	{
		int hospNum = 0;
		boolean deleted;
		try{
			System.out.print("Enter hospitalization number : ");
			hospNum = Integer.parseInt(input.readLine());
		}catch (Exception e)
		{
			System.out.println("Invalid input for a number");
			return;
		}
	
		/**	Make sure that patient exists */
		patNumToPatFile.search(new Integer(hospNum));
		if (patNumToPatFile.itemExists())
		{
			PatientUos deletionPatient = (PatientUos)patNumToPatFile.item();
			patNumToPatFile.deleteItem();
		
			/**	Delete the doctor patient pair from the file */
			String deletionDoc = deletionPatient.docName();
			ComparablePairUos deleteDocPat = new ComparablePairUos(deletionDoc, new Integer(hospNum));
			doctorToPatNumFile.delete(deleteDocPat);
			
			/** Delete the drug patient pair from the file */
			String deletionDrug = deletionPatient.drugName();
			ComparablePairUos deleteDrugPat = new ComparablePairUos(deletionDrug, new Integer(hospNum));
			drugToPatNumFile.delete(deleteDrugPat);
			
			/** Delete the patient record from the file */
			patNameToPatNumFile.delete(deletionPatient.name());
			
			/** Delete the bed record from the file */
			bedToPatNumFile.delete(new Integer(deletionPatient.bedNum()));
		} 
		else
			System.out.println("Invalid hospitalization number");
	}

	/**	Output a user specified patient by patient's name. <br>
		Analysis: Time = O(search()) + O(obtain()) for patNameToPatNumFile */
	public void searchByPatName()
	{
		String patName = null;
		System.out.print("Enter the patient's name : ");
		try{
			patName = input.readLine();
		}catch (Exception e)
		{
			System.out.println("Invalid input");
			return;
		}
		patNameToPatNumFile.search(patName);
		if (patNameToPatNumFile.itemExists())
		{
			Integer patNum = (Integer) patNameToPatNumFile.item();
			PatientUos pat = (PatientUos) patNumToPatFile.obtain(patNum);
			System.out.println("The desired patient is\n" + pat.toString());
		}
		else
			System.out.println("No patient by the name " + patName + " in the system");
	}

	/**	Output the list of patients by user specified doctor 's name. <br>
		Analysis: Time = O(search()) + O(obtain()) for doctorToPatNumFile */
	public void searchByDocName()
	{
		String docName = null;
		System.out.print("Enter the doctor's name : ");
		try{
			docName = input.readLine();
		}catch (Exception e)
		{
			System.out.println("Invalid input");
			return;
		}
	
		/* Move to the first pair for this doctor, the pair with hospitalization number -1. */
		ComparablePairUos firstDocPatNumPair = new ComparablePairUos(docName, new Integer(-1));
		doctorToPatNumFile.search(firstDocPatNumPair);
		if (!doctorToPatNumFile.itemExists())
			System.out.println("There is no doctor by the name " + docName);
		else
		{
			doctorToPatNumFile.goForth();
			System.out.println("The patients for Doctor " + docName + " are");
			ComparablePairUos nextDocPatNumPair = (ComparablePairUos) doctorToPatNumFile.itemKey();
			while(docName.equals(nextDocPatNumPair.firstItem()))
			{
				Integer patNum = (Integer) (nextDocPatNumPair.secondItem());
				PatientUos pat = (PatientUos) patNumToPatFile.obtain(patNum);
				System.out.println(pat.toString());
				doctorToPatNumFile.goForth();
				if(doctorToPatNumFile.after())
					break;
				else
					nextDocPatNumPair = (ComparablePairUos)doctorToPatNumFile.itemKey();
			}
		}
	}

	/**	Ouput the list of patients by user specified drug's name. <br>
		Analysis: Time = O(search()) + O(obtain()) for drugToPatNumFile */
	public void searchByDrug()
	{
		String drugName = null;
		System.out.print("Enter the drug name : ");
		try{
			drugName = input.readLine();
		}catch (Exception e)
		{
			System.out.println("Invalid input");
			return;
		}
	
		/* Move to the first pair for this drug, the pair with hospitalization number -1. */
		ComparablePairUos firstDrugPatNumPair = new ComparablePairUos(drugName, new Integer(-1));
		drugToPatNumFile.search(firstDrugPatNumPair);
		if (!drugToPatNumFile.itemExists())
			System.out.println("There is no drug by the name " + drugName);
		else
		{
			drugToPatNumFile.goForth();
			System.out.println("The patients for drug " + drugName + " are");
			ComparablePairUos nextDrugPatNumPair = (ComparablePairUos) drugToPatNumFile.itemKey();
			while(drugName.equals(nextDrugPatNumPair.firstItem()))
			{
				Integer patNum = (Integer) (nextDrugPatNumPair.secondItem());
				PatientUos pat = (PatientUos) patNumToPatFile.obtain(patNum);
				System.out.println(pat.toString());
				drugToPatNumFile.goForth();
				if(drugToPatNumFile.after())
					break;
				else
					nextDrugPatNumPair = (ComparablePairUos)drugToPatNumFile.itemKey();
			}
		}
	}

	/**	Output the patient by user specified bed number. <br>
		Analysis: Time = O(search()) + O(obtain()) for bedToPatNumFile */
	public void searchByBed()
	{
		int bedNum = -1;
		System.out.print("Enter the bed number : ");
		try{
			bedNum = Integer.parseInt(input.readLine());
		}catch (Exception e)
		{
			System.out.println("Invalid input for a number");
			return;
		}
		bedToPatNumFile.search(new Integer(bedNum));
		if (bedToPatNumFile.itemExists())
		{
			Integer patNum = (Integer) bedToPatNumFile.item();
			PatientUos pat = (PatientUos) patNumToPatFile.obtain(patNum);
			System.out.println("The desired patient is \n" + pat.toString());
		}
		else
			System.out.println("There is no patient in the bed with number " + bedNum);
	}

	/**	Output the patient by user specified hospitalization number. <br>
		Analysis: Time = O(search()) + O(obtain()) for patNumToPatFile */
	public void searchByHospNum()
	{
		int hospNum = -1;
		System.out.print("Enter the hospitalization number : ");
		try{
			hospNum = Integer.parseInt(input.readLine());
		}catch (Exception e)
		{
			System.out.println("Invalid input for a number");
			return;
		}
		patNumToPatFile.search(new Integer(hospNum));
		if (patNumToPatFile.itemExists())
		{
			PatientUos pat = (PatientUos) patNumToPatFile.item();
			System.out.println("The desired patient is \n" + pat.toString());
		}
		else
			System.out.println("There is no patient with hospitalization number " + hospNum);
	}

	/**	Exit the system. <br>
		Analysis: Time = O(1) */
	public void exitSys()
	{
		((BtreeFileUos)patNumToPatFile).closeFile();
			((BtreeFileUos)doctorToPatNumFile).closeFile();
			((BtreeFileUos)drugToPatNumFile).closeFile();
			((BtreeFileUos)patNameToPatNumFile).closeFile();
			((BtreeFileUos)bedToPatNumFile).closeFile();
			System.out.println("\nSystem terminated by user");
		}
		
	/**	Display the entire list of patients. <br>
		Analysis: Time = size of patNumToPatFile. */
	public void outputPatientList()
	{
		System.out.println("CURRENT PATIENTS");
		System.out.println("-----------------");
		for (patNumToPatFile.goFirst(); !patNumToPatFile.after(); patNumToPatFile.goForth())
			System.out.println(patNumToPatFile.item());
	}

	/**	Main method of the class. <br>
		Analysis: Time = O(numbers of the queries * time for each query) */
	public static void main(String[] args)
	{
		new HospitalSysUos();
	}
}