tut10

 */import java.util.Scanner;
public class JavaApplication22 {
        public static void BMI(){
         Scanner a = new Scanner(System.in);
         System.out.println("Please enter your weight in kilogram");
         double weight = a.nextDouble();
         System.out.println("Please enter your height in meter");
         double height = a.nextDouble();
         double BMI = (weight/(height*height));
         System.out.println("Your BMI rating is " + BMI);
        }
        public static void coin(){
          Scanner b = new Scanner(System.in);
          System.out.println("Please enter your amount of coins");
          int coin = b.nextInt();
          int quan = coin/10000;
          int dong = coin%10000/100;
          int hao = coin%10000%100/10;
          int xu = coin%10000%100%10;
          System.out.println("You have " + quan + " quan, " + dong + " dong, " + hao + " hao, " + xu + " xu.");
        }
        public static void leap(){
         Scanner c = new Scanner(System.in);
         System.out.println("Please enter the year you want to check");
          int y = c.nextInt();
                String a = "The year " + y + " is not a leap year";
                String b = "The year " + y + " is a leap year";
                if (y % 4 != 0){
                    System.out.println(a);
                }else
                    if (y % 100 != 0 ){
                    System.out.println(b);
                }else
                    if ( y % 400 != 0 ){
                        System.out.println(a);
                }else
                        System.out.println(b);
        }
        public static void quadratic(){
        	int a, b, c;
        double root1, root2, d;
        Scanner s = new Scanner(System.in);
        System.out.println("Given quadratic equation:ax^2 + bx + c");
        System.out.print("Enter a:");
        a = s.nextInt();
        System.out.print("Enter b:");
        b = s.nextInt();
        System.out.print("Enter c:");
        c = s.nextInt();
        System.out.println("Given quadratic equation:"+a+"x^2 + "+b+"x + "+c);
        d = b * b - 4 * a * c;
        	if (a==0 && b==0 && c==0){
            System.out.println("There is nothing to be solved");
        }else
        	 if (a==0 && b==0 && c != 0){
            System.out.println("The equation has no root");
        }else
        	 if (a==0 && b !=0 && c !=0){
            double x = -c/b;
            System.out.println("X= " + x);
        }else
        	 if (d < 0){
            System.out.println("The equation has no real root");
        }else
        	 if (d > 0){
            double x1 = ((-b + Math.sqrt(b*b-4*a*c))/(2*a));
            double x2 = ((-b - Math.sqrt(b*b-4*a*c))/(2*a));
            System.out.println("The equation has two roots : x1 = " +x1 + "," + "x2 = " +x2);
        }
        }
        public static void strength(){
        	Scanner e = new Scanner(System.in);
        System.out.println("Please enter the password you wish to be evaluated");
        String password= e.nextLine();
        int strength= 0;
        boolean upper= false, lower= false, digit= false, symbol= false;
        if (password.length()>=8 && password.length()<=12)
        {
            strength+=1;
        }
        else if (password.length()>12)
        {
            strength+=2;
        }
        for (int i=0; i< password.length(); ++i) // uppercase checker
        {
            if (password.charAt(i)>= 'A' && password.charAt(i)<= 'Z')
            {
                upper= true;
                continue;
            }
            else if (password.charAt(i)>= 'a' && password.charAt(i)<= 'z')
            {
                lower= true;
                continue;
            }
            else if (password.charAt(i)>= '0' && password.charAt(i)<= '9')
            {
                digit= true;
                continue;
            }
            else
            {
                symbol= true;
            }
        }
        if (upper == true)
        {
            strength+=1;
        }
        if (lower == true)
        {
            strength+=1;
        }
        if (digit == true)
        {
            strength+=1;
        }
        if (symbol == true)
        {
            strength+=1;
        }
        if (strength<=2)
        {
            System.out.println("Your password strength: " + strength+ " (weak)");
        }
        else if (strength <=4)
        {
            System.out.println("Your password strength: " + strength+ " (medium)");
        }
        else
        {
            System.out.println("Your password strength: " + strength+ " (strong). Make sure you do not forget it.");
        }

        }
        public static void GCD(){
        	Scanner f= new Scanner(System.in);
        System.out.println("Enter two positive integers of which you wish to find the GCD");
        int a= f.nextInt();
        int b= f.nextInt();
        while (a<=0 || b<=0)
        {
            System.out.println("The program does not allow negative or zero values! Please try again.");
            a= f.nextInt();
            b= f.nextInt();
        }
        if (a<b)
        {
            int temp= a;
            a=b;
            b=temp;
        }
        while (true)
        {
            if (a%b==0)
            {
                break;
            }
            int temp=a;
            a= b;
            b= temp%b;
        }
        System.out.println("The GCD is: "+ b);
        }
    public static void main(String[] args) {
         Scanner f = new Scanner(System.in);
        System.out.println("[1] BMI calculator");
        System.out.println("[2] Coin converter");
        System.out.println("[3] Leap year checker");
        System.out.println("[4] Quadratic equation solver");
        System.out.println("[5] Password strength meter");
        System.out.println("[6] GCD finder");
        System.out.println("[7] Quit");
        System.out.println("Choose an option");
        int n = f.nextInt();
        while (n !=7)
        {
            switch (n)
            {
            case 1:
            	BMI();
                break;
            case 2:
                coin();
                break;
            case 3:
                leap();
                break;
            case 4:
                quadratic();
                break;
            case 5:
            	strength();
            	break;
            case 6:
            	GCD();
            	break;
            }
            System.out.println("[1] BMI calculator");
            System.out.println("[2] Coin converter");
            System.out.println("[3] Leap year checker");
            System.out.println("[4] Quadratic equation solver");
            System.out.println("[5] Password strength finder");
            System.out.println("[6] GCD finder");
            System.out.println("[7] Quit");
            System.out.println("Choose an option");
            n = f.nextInt();
        }
        System.out.println("Program exited");
    }
}