Binary search algorithm

BinarySearch.java

package com.example.demo;

public class BinarySearch {

    int binarySearch(int[] a, int n, int left, int right) {
        if (left > right) return -1;
        int mid = (left + right) / 2;
        if (n < a[mid]) {
            return binarySearch(a, n, 0, mid - 1);
        }
        if (n > a[mid]) {
            return binarySearch(a, n, mid + 1, right);
        }
        return mid;
    }

}