// Java program to demonstrate working of Collections.
// binarySearch()
import java.util.List;
import java.util.ArrayList;
import java.util.Collections;

public class GFG
{
    public static void main(String[] args)
    {
        List<Integer> al = new ArrayList<Integer>();
        al.add(1);
        al.add(2);
        al.add(3);
        al.add(10);
        al.add(20);

        // 10 is present at index 3.
        int key = 10;
        int res = Collections.binarySearch(al, key);
        if (res >= 0)
            System.out.println(key + " found at index = "
                                                 + res);
        else
            System.out.println(key + " Not found");

        key = 15;
        res = Collections.binarySearch(al, key);
        if (res >= 0)
            System.out.println(key + " found at index = "
                                                  + res);
        else
            System.out.println(key + " Not found");
    }
}