Binary search

package gfg;

//Binary search

import java.io.*;
import java.util.*;

  public class GFG {

    public static void main(String[] args) throws IOException {
        Scanner sc = new Scanner(System.in);
        int T = sc.nextInt();

        while (T > 0) {
            int n = sc.nextInt();
            int arr[] = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = sc.nextInt();
            }

            int key = sc.nextInt();
            Solution g = new Solution();
            System.out.println(g.binarysearch(arr, n, key));
            T--;
        }
    }
}

class Solution {
    int binarysearch(int arr[], int n, int k) {
        // code here
        int left = 0;
        int right = n - 1;
        
        while(left <= right) {
            int mid = (right + left) / 2;
            if(arr[mid] == k) {
                return mid;
            }
            
            else if(arr[mid] > k) {
                right = mid - 1;
            }
            
            else {
                left = mid + 1;
            }
        }
        
        return -1;
    }
}