Binary Search

 

Sample Input 1:

5
2
1 2 3 4 5

Sample Output 1:

1

import java.util.Scanner;

public class BinarySearch {

	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		int n=s.nextInt();
		int x=s.nextInt();
		int a[]=new int[n];
		for(int i=0;i<n;i++)
		{
			a[i]=s.nextInt();
		}
		int ab=binarySearch(a, x);
		System.out.println(ab);

	}
	public static int binarySearch(int[] arr, int x) {
		
		int l=0;
		int e=arr.length-1;
		
		while(l<=e)
		{
			int m=(l+e)/2;
			if(arr[m]==x)
			{
				return m;
			}
			else if(arr[m]>x)
			{
				e=m-1;
			}
			else
			{
				l=m+1;
			}
		}
		return -1;
}
}