Ques1 Week 5 OOP

import java.util.*;
import static java.lang.System.out;
class Student {
	int RegNumber;
	String FullName;
	GregorianCalendar Date;
	short Semester;
	float GPA, CGPA;
	public static int count = 1;
	Student () {
		RegNumber = 0;
		FullName = new String("");
		Date = new GregorianCalendar();
		Semester = 0;
		GPA = 0.0f;
		CGPA = 0.0f;
	}
	Student (int RN, String FN, GregorianCalendar DT, short SM, float G, float CG) {
		RegNumber = RN;
		FullName = new String(FN);
		Date = DT;
		Semester = SM;
		GPA = G;
		CGPA = CG;
	}
	Student (Student tmp) {
		RegNumber = tmp.RegNumber;
		FullName = new String(tmp.FullName);
		Date = tmp.Date;
		Semester = tmp.Semester;
		GPA = tmp.GPA;
		CGPA = tmp.CGPA;
	}
	void display(Student tmp) {
		out.println("Student #" + tmp.RegNumber + " Details: ");
		out.println();
		out.println("Registeration Number - " + tmp.RegNumber);
		out.println("Full Name - " + tmp.FullName);
		out.println("Date of Joining - " + tmp.Date);
		out.println("Semester - " + tmp.Semester);
		out.println("GPA - " + tmp.GPA);
		out.println("CGPA - " + tmp.CGPA);
		out.println();
	}
	void setDateNRegNum(Student tmp) {
		Calendar calendar = new GregorianCalendar();
		int year = calendar.get(Calendar.YEAR);
		int month = calendar.get(Calendar.MONTH);
		int day = calendar.get(Calendar.DAY_OF_MONTH);
		tmp.Date = new GregorianCalendar(day, month, year);
		tmp.RegNumber = year % 10 * 100;
		year /= 10;
		tmp.RegNumber += year % 10 * 1000;
		tmp.RegNumber += tmp.count;
		tmp.count++;
	}
	static void sortSem(Student[] s) {
		Student stemp = new Student();
		for(int i = 0; i < 5; i++) {
		int index = i;
		for (int j = i + 1; j < 5; j++)
		if (s[j].Semester < s[index].Semester)
		index = j;
		stemp = s[index];
		s[index] = s[i];
		s[i] = stemp;
		}
	}
	static void sortCgpa(Student[] s) {
		Student stemp = new Student();
		for(int i = 0; i < 5; i++) {
		int index = i;
		for (int j = i + 1; j < 5; j++)
		if (s[j].CGPA < s[index].CGPA)
		index = j;
		stemp = s[index];
		s[index] = s[i];
		s[i] = stemp;
		}
	}
	static void sortName(Student[] s) {
		Student stemp = new Student();
		for(int i = 0; i < 5; i++) {
		int index = i;
		for (int j = i + 1; j < 5; j++)
		if (((s[j].FullName).compareTo(s[index].FullName)) < 0)
		index = j;
		stemp = s[index];
		s[index] = s[i];
		s[i] = stemp;
		}
	}
}
class StudentDemo {
	public static void main (String args[]) {
		clrScr();
		Scanner in = new Scanner(System.in);
		int opt, N, i;
		String b = "\033[1m", ub = "\033[0m";
		out.print("Enter number of students: ");
		N = in.nextInt();
		out.println();
		Student []stud = new Student[N];
		do {
			out.println(b + " --- STUDENT DATABASE --- " + ub);
			out.println();
			out.println("1. Input Student Data");
			out.println("2. Display Student Data");
			out.println("3. Sort [Semester]");
			out.println("4. Sort [CGPA]");
			out.println("5. Sort [Name]");
			out.println("6. Search [Character]");
			out.println("7. Search [Sub String]");
			out.println("8. Convert to Initials");
			out.println("9. Exit");
			out.println();
			out.print("Option : ");
			opt = in.nextInt();
			out.println();
			switch (opt) {
				case 1: clrScr();
					for(i = 0; i < N; i++) {
						out.println(b + "Enter Student #" + (i+1) + " Data: " + ub);
						out.println();
						stud[i] = new Student();
						stud[i].setDateNRegNum(stud[i]);
						out.println("Registeration Number - " + stud[i].RegNumber);
						out.print("Full Name - ");
						stud[i].FullName = in.next();
						out.println("Date of Joining - " + stud[i].Date.get(Calendar.DAY_OF_MONTH) + "/" + stud[i].Date.get(Calendar.MONTH) + "/" + stud[i].Date.get(Calendar.YEAR));
						out.print("Semester - ");
						stud[i].Semester = in.nextShort();
						out.print("GPA - ");
						stud[i].GPA = in.nextInt();
						out.print("CGPA - ");
						stud[i].CGPA = in.nextInt();
						clrScr();
					}
					out.println();
					out.println(b + "All data entered!" + ub);
					pressAnyKeyToContinue();
					clrScr();
					break;
				case 2: clrScr();
					out.println(b + "All Student Data: " + ub);
					out.println();
					for(i = 0; i < N; i++) {
						out.println(b + "Student #" + (i+1) + " Data: " + ub);
						out.println();
						out.println("Registeration Number - " + stud[i].RegNumber);
						out.println("Full Name - " + stud[i].FullName);
						out.println("Date of Joining - " + stud[i].Date.get(Calendar.DAY_OF_MONTH) + "/" + stud[i].Date.get(Calendar.MONTH) + "/" + stud[i].Date.get(Calendar.YEAR));
						out.println("Semester - " + stud[i].Semester);
						out.println("GPA - " + stud[i].GPA);
						out.println("CGPA - " + stud[i].CGPA);
						out.println();
					}
					out.println();
					out.println(b + "All data displayed!" + ub);
					pressAnyKeyToContinue();
					clrScr();
					break;
				case 3: clrScr();
					Student.sortSem(stud);
					out.println();
					out.println(b + "All Student Data: " + ub);
					out.println();
					for(i = 0; i < N; i++) {
						out.println(b + "Student #" + (i+1) + " Data: " + ub);
						out.println();
						out.println("Registeration Number - " + stud[i].RegNumber);
						out.println("Full Name - " + stud[i].FullName);
						out.println("Date of Joining - " + stud[i].Date.get(Calendar.DAY_OF_MONTH) + "/" + stud[i].Date.get(Calendar.MONTH) + "/" + stud[i].Date.get(Calendar.YEAR));
						out.println("Semester - " + stud[i].Semester);
						out.println("GPA - " + stud[i].GPA);
						out.println("CGPA - " + stud[i].CGPA);
						out.println();
					}
					out.println();
					out.println(b + "All sorted and data displayed!" + ub);
					pressAnyKeyToContinue();
					clrScr();
					break;
				case 4: clrScr();
					Student.sortCgpa(stud);
					out.println();
					out.println(b + "All Student Data: " + ub);
					out.println();
					for(i = 0; i < N; i++) {
						out.println(b + "Student #" + (i+1) + " Data: " + ub);
						out.println();
						out.println("Registeration Number - " + stud[i].RegNumber);
						out.println("Full Name - " + stud[i].FullName);
						out.println("Date of Joining - " + stud[i].Date.get(Calendar.DAY_OF_MONTH) + "/" + stud[i].Date.get(Calendar.MONTH) + "/" + stud[i].Date.get(Calendar.YEAR));
						out.println("Semester - " + stud[i].Semester);
						out.println("GPA - " + stud[i].GPA);
						out.println("CGPA - " + stud[i].CGPA);
						out.println();
					}
					out.println();
					out.println(b + "All sorted and data displayed!" + ub);
					pressAnyKeyToContinue();
					clrScr();
					break;
				case 5: clrScr();
					Student.sortName(stud);
					out.println();
					out.println(b + "All Student Data: " + ub);
					out.println();
					for(i = 0; i < N; i++) {
						out.println(b + "Student #" + (i+1) + " Data: " + ub);
						out.println();
						out.println("Registeration Number - " + stud[i].RegNumber);
						out.println("Full Name - " + stud[i].FullName);
						out.println("Date of Joining - " + stud[i].Date.get(Calendar.DAY_OF_MONTH) + "/" + stud[i].Date.get(Calendar.MONTH) + "/" + stud[i].Date.get(Calendar.YEAR));
						out.println("Semester - " + stud[i].Semester);
						out.println("GPA - " + stud[i].GPA);
						out.println("CGPA - " + stud[i].CGPA);
						out.println();
					}
					out.println();
					out.println(b + "All sorted and data displayed!" + ub);
					pressAnyKeyToContinue();
					clrScr();
					break;
				case 6: break;
				case 7: break;
				case 8: break;
				case 9: break;
				default: break;
			}
		}while(opt != 9);
	}
	public static void pressAnyKeyToContinue() { 
		out.println("Press any key to continue...");
		try {
		    System.in.read();
		}  
		catch(Exception e) {}  
 	}
	public static void clrScr() { 
		out.print("\033\143");  
 	}
	
}