RecursiveBinarySearch.java

// Code by Pronay Debnath
// Created:- 1/10/2023
// File Name should be RecursiveBinarySearch.java
// Explanation:- https://www.tutorialspoint.com/java-program-for-binary-search-recursive

import java.util.*;

public class RecursiveBinarySearch<T extends Comparable<T>> {

    // Recursive binary search function
    public int binsear(T[] arr, int left, int right, T target) {
        if (right >= left) {
            int mid = left + (right - left) / 2;

            // Compare the element at the middle with the target
            int comparison = arr[mid].compareTo(target);

            // If the element is equal to the target, return its index
            if (comparison == 0) {
                return mid;
            }

            // If the element is greater than the target, search in the left subarray
            if (comparison > 0) {
                return binsear(arr, left, mid - 1, target);
            }

            // Otherwise, search in the right subarray
            return binsear(arr, mid + 1, right, target);
        }

        // Element is not present in the array
        return -1;
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        // User inputs
        System.out.print("Enter the number of elements in the array: ");
        int n = sc.nextInt();

        Integer[] a = new Integer[n]; // You can change the array type as needed

        System.out.println("Enter the elements in sorted order:");

        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
        }

        System.out.print("Enter the target element to search for: ");
        int t = sc.nextInt();

        RecursiveBinarySearch<Integer> searcher = new RecursiveBinarySearch<>();
        int res = searcher.binsear(a, 0, n - 1, t);

        if (res == -1)
            System.out.println("Element not found in the array.");
        else
            System.out.println("Element found at index " + res);
    }
}