Java Binary Search

Check Even or Odd number

import java.util.Scanner;

          class CheckEvenOdd

          {

public static void main(String args[])

          {

    int num;

    System.out.println("Enter an Integer number:");

    Scanner input = new Scanner(System.in);

    num = input.nextInt();

                if ( num % 2 == 0 )

        System.out.println("Entered number is even");

     else

        System.out.println("Entered number is odd");

  }

}

Java program for linear search

import java.util.Scanner;

class LinearSearchExample

{

 public static void main(String args[])

 {

      int counter, num, item, array[];

      Scanner input = new Scanner(System.in);

      System.out.println("Enter number of elements:");

      num = input.nextInt(); 

      array = new int[num]; 

      System.out.println("Enter " + num + " integers");

      for (counter = 0; counter < num; counter++)

        array[counter] = input.nextInt();

               System.out.println("Enter the search value:");

      item = input.nextInt();

       for (counter = 0; counter < num; counter++)

       {

         if (array[counter] == item) 

         {

           System.out.println(item+" is present at location "+(counter+1));

           break;

         }

      }

      if (counter == num)

        System.out.println(item + " doesn't exist in array.");

   }

}

Perform binary search

import java.util.Scanner;

class BinarySearchExample

{

   public static void main(String args[])

   {

      int counter, num, item, array[], first, last, middle;

      Scanner input = new Scanner(System.in);

      System.out.println("Enter number of elements:");

      num = input.nextInt(); 

      array = new int[num];

               System.out.println("Enter " + num + " integers");

      for (counter = 0; counter < num; counter++)

          array[counter] = input.nextInt();

      System.out.println("Enter the search value:");

      item = input.nextInt();

      first = 0;

      last = num - 1;

      middle = (first + last)/2;

               while( first <= last )

      {

         if ( array[middle] < item )

           first = middle + 1;

         else if ( array[middle] == item )

         {

           System.out.println(item + " found at location " + (middle + 1) + ".");

           break;

         }

         else

         {

             last = middle - 1;

         }

         middle = (first + last)/2;

      }

      if ( first > last )

          System.out.println(item + " is not found.\n");

   }

}

Print Floyd’s triangle

import java.util.Scanner;

class FloydTriangleExample

{

    public static void main(String args[])

    {

       int rows, number = 1, counter, j;

       Scanner input = new Scanner(System.in);

       System.out.println("Enter the number of rows for floyd's triangle:");

       rows = input.nextInt();

       System.out.println("Floyd's triangle");

       System.out.println("****************");

       for ( counter = 1 ; counter <= rows ; counter++ )

       {

           for ( j = 1 ; j <= counter ; j++ )

           {

                System.out.print(number+" ");

                number++;

           }

                   System.out.println();

       }

   }

}

Reverse a number using for, while and recursion

import java.util.Scanner;

class ReverseNumberWhile

{

   public static void main(String args[])

   {

      int num=0;

      int reversenum =0;

      System.out.println("Input your number and press enter: ");

      Scanner in = new Scanner(System.in);

      num = in.nextInt();

      while( num != 0 )

      {

          reversenum = reversenum * 10;

          reversenum = reversenum + num%10;

          num = num/10;

      }

      System.out.println("Reverse of input number is: "+reversenum);

   }

}