IterativeBinarySearch.java

import java.util.Arrays;
/**
 * Java program to implement Binary Search. We have implemented Iterative
* version of Binary Search Algorithm in Java
*
* @author Javin Paul
*/
public class IterativeBinarySearch {
  public static void main(String args[]) {
    int[] list = new int[]{23, 43, 31, 12};
    int number = 12;
    Arrays.sort(list);
    System.out.println("Binary Search " + number + " in integer array" + Arrays.toString(list));
    binarySearch(list, 12);
    int num2 = 43;
    System.out.println("Binary Search" + num2+ " in integer array "+ Arrays.toString(list));
    binarySearch(list, 43);
    list = new int[]{123, 243, 331, 1298};
    number = 331;
    Arrays.sort(list);
    System.out.println("Binary Search "+number +" in integer array "+ Arrays.toString(list));
    binarySearch(list, 331);

    System.out.println("Binary Search " +number+" in integer array "+ Arrays.toString(list));
    binarySearch(list, 1333);
   // Using Core Java API and Collection framework
   // Precondition to the Arrays.binarySearch
  Arrays.sort(list);
   // Search an element
  int index = Arrays.binarySearch(list, 3);
}
/**
 * Perform a binary Search in Sorted Array in Java
 * @param input
 * @param number
 * @return location of element in array
 */
public static void binarySearch(int[] input, int number) {
int first = 0;
int last = input.length - 1;
int middle = (first + last) / 2;
while (first <= last) {

  if (input[middle] < number)
  {
  first = middle + 1;
  }
  else if (input[middle] == number)
  {
	System.out.printf(number + " found at location %d %n", middle);
	break;
  }
  else
  {
  last = middle - 1;
  }

  middle = (first + last) / 2;
  }

      if (first > last) {
        System.out.println(number + " is not present in the list.\n");
      }
  }
}