its101.md.wk.08.09.BinarySearch

package its101.mdwk08_09;

import java.util.Arrays;

public class BinarySearchFinal {

    //     Create function binarySearch()
    public static int binarySearch(int[] array, int lowerBound, int upperBound, int key) {
        if (upperBound >= lowerBound) {
            //  Set midPoint
            int midPoint = lowerBound + (upperBound - lowerBound) / 2;
            //  If key is found, then return its index position
            if (array[midPoint] == key) {
                return midPoint;
            }
            //  If key is smaller than midPoint, the key is in the left sub array
            if (array[midPoint] > key) {
                return binarySearch(array, lowerBound, midPoint - 1, key);
            }
            //  If key is larger than midPoint, the key is in the right sub array
            return binarySearch(array, midPoint + 1, upperBound, key);
        }
        //  If key is not found, then return -1
        return -1;
    } //    End of function binarySearch()

    public static void main(String[] args) {

        // Create new array
        int[] myArray = {3, 4, 5, 6, 7, 8, 9};
        //  Set upperBound
        int upperBound = myArray.length - 1;

        // Print array
        System.out.println(Arrays.toString(myArray));

        // Initiate element key to be search
        int key = 4;
        // Initiate the search result using the binarySearch() function
        int result = binarySearch(myArray, 0, upperBound, key);

        // If-else statement for printing the result
        if (result != -1) {
            System.out.println("Element " + key + " is present at index " + result);
        } else {
            System.out.println("Element " + key + " is not present in the array");
        }
    }
}