TaskFive.java

import java.util.Scanner;
public class TaskFive {
  public static int binarySearch(int[] number, int key){    
	int start = 0;
        int end = number.length - 1;
        while (start <= end) {
            int mid = (start + end) / 2;
            if (key == number[mid]) {
                return mid;
            }
            if (key < number[mid]) {
                end = mid - 1;
            } else {
                start = mid + 1;
            }
        }
        return -1;  
    }    
 
    public static void main(String args[]){
	Scanner input= new Scanner(System.in);


	 int[]number={2,5,8,3,4,6,10,15,20,1,11};
    
        int key = input.nextInt();   
        System.out.println(key+" is found at index: "+binarySearch(number, key));  
   }
}