BinarySearch.java

import org.w3c.dom.ls.LSOutput;

public class BinarySearch {
    public static void main(String[] args) {
        int[] arr = {-18, -12, -4, 0, 2, 3, 4, 15, 16, 18, 22, 45, 89};
        int ans = binarySearch(arr,22 );
        System.out.println(ans);
    }

    static int binarySearch(int[] arr, int target){
        int start=0;
        int end=arr.length-1;
        
        while(start<=end){
            // find the middle element
//            int mid = (start +end)/2;  // might be possible that (start+end) exceeds the range of int in java
            int mid = start + (end-start)/2;
            
            if (target<arr[mid]){
                end=mid-1;
            } else if (target>arr[mid]) {
                start=mid+1;
            }
            else{
                // ans found
                return mid;
            }
        }
        return -1;
    }
}