Source Codes

 

 

Ex1

//list integers whose sum of odd digits are equal

//to sum of even digits...

 

import java.util.Scanner;

 

public class SumEEqSumO{

    public static void main (String[] args){

        int N, r = 0;

      int b,p,sume = 0,sumo = 0,t,tt;

      boolean isEq;

     

            Scanner keyboard = new Scanner(System.in);

 

            System.out.print("Enter how many?: ");

          b = keyboard.nextInt();

 

      p = 1;

          

        while(p<=b){

            isEq = false; //sumEven != sumOdd

                 

            while(!isEq){

                        r = (int)(Math.random()*2000000000+1);

                  tt = r;

                sume = 0;

                sumo = 0;

                       

                  while(tt > 0){

                        t = tt%10;

                        if(t%2 == 0)

                              sume = sume+t;

                        else

                              sumo = sumo+t;

                        tt = tt/10;

                  }

                  isEq = sume == sumo; //stop the loop

           }

           System.out.println(r + "  " + sume + "  " + sumo);

                  p++;

      }

    }

}

 

Ex2

//create random password

 

import java.util.Scanner;

 

public class Password1

{

    public static void main(String[] args)

    {

            Scanner keyboard = new Scanner(System.in);

   

      String password = "";

      int rand, rand1, length, i;

      char c;

           

            System.out.print("Enter length: ");

            length = keyboard.nextInt();

           

            i = 1;

           

            rand = (int)(Math.random()*length + 1);

           

            System.out.println("Random number is " + rand);

 

            while(i <= rand){

                  rand1 = (int)(Math.random()*26 + 65);

                  c = (char)rand1;

                  password = password + c;

                  i++;

            }

           

            i = 1;

            while(i <= length-rand){

                  c = (char)(int)(Math.random()*26 + 97);

                  password = password+c;

                  i++;

            }

           

            System.out.println(password);

      }

}

 

Ex3

 

//string methods

 

import java.util.Scanner;

 

 

public class StaticDemos

{

    public static void main(String[] args)

    {

      Scanner kb = new Scanner(System.in);

     

      String s,ss;

 

            System.out.print("Enter string: ");

      s = kb.nextLine();

     

            System.out.print("Enter substring: ");

      ss = kb.next();

     

      System.out.println(howMany(s,ss));

     

     

            /*System.out.println(reverse(s));

     

      if(isPalindrome(s))

            System.out.println("Palindrome");

      else

            System.out.println("No");*/

     

    }

   

    private static boolean isPalindrome (String s) {

        int lastPosition = s.length() - 1;

        int forward = 0;

        int backward = lastPosition;

        while (forward < backward) {

            if (s.charAt(forward) != s.charAt(backward))

                return false;

            else {

                forward++;

                backward--;

            }

        }

        return true;

    }

   

    private static String upperCase (String s){

        String t="";

        char c;

        for (int i=0; i<s.length();i++){

            c = s.charAt(i);

            if(c>='a' && c<='z')

                  t = t+(char)((int)s.charAt(i)-32);

               

            else

                t = t+s.charAt(i);

        }

        return t;

    }

   

    private static String removeSpaces(String s){

      String r="";

      for(int i=0;i<s.length();i++)

            if(s.charAt(i) != ' ')

                  r = r+s.charAt(i);

      return r;

    }

 

    private static String reverse(String s){

      String rev = "";

      for (int i = s.length()-1; i>=0; i--)

            rev = rev + s.charAt(i);

        return rev;  

    }

 

    private static int howMany(String s, String ss){

            int L = ss.length();

            int cnt = 0;

 

            int i = 0;

            while(s.indexOf(ss,i)!=-1){

                  cnt++;

                  i = s.indexOf(ss,i)+L;

            }

     

            return cnt;

      }

}

   

Ex 4

 

//represent fraction

public class Fraction

{

    private int denominator, numerator;

 

    public Fraction (int numerator, int denominator)

    {

        this.numerator = numerator;

        this.denominator = denominator;

    }

   

    public void setNumerator (int numerator)

    {

        this.numerator = numerator;

    }

   

    public void setDenominator (int denominator)

    {

        this.denominator = denominator;

    }

   

    public double getNumerator ()

    {

      return (double)numerator;

    }

 

    public double getDenominator ()

    {

      return (double)denominator;

    }

   

    private static int GCD (int small, int large)

    {

      int div;

     

      for (div = small; div > 0; div--)

      {

            if (large%div == 0 && small%div == 0)

                  return div;

      }

      return div;

    }

   

    public void simplify ()

    {

      int div = GCD (numerator, denominator);

      numerator = numerator / div;

      denominator = denominator / div;

    }

 

    public String toString ()

    {

      String s = numerator + " / " + denominator;

      return s;

    }

}

 

//Fraction class test program

import java.util.Scanner;

 

public class FractionTest

{

    public static void main(String[] args)

    {

      Scanner keyboard = new Scanner (System.in);

     

      int num, denom;

     

      System.out.println ("Enter numerator: ");

            num = keyboard.nextInt ();

           

      System.out.println ("Enter denominator: ");

            denom = keyboard.nextInt ();

     

      Fraction f = new Fraction (num, denom);

        System.out.println (f);

       

        System.out.println (f.getNumerator() / f.getDenominator());

       

        f.simplify ();

        System.out.println (f);

    }

}