Binary Search Top Interview Problems

`// Java implementation of iterative Binary Search

import java.io.*;

class BinarySearch {

// Returns index of x if it is present in arr[].
int binarySearch(int arr[], int x)
{
    int low = 0, high = arr.length - 1;
    while (low <= high) {
        int mid = low + (high - low) / 2;

        // Check if x is present at mid
        if (arr[mid] == x)
            return mid;

        // If x greater, ignore left half
        if (arr[mid] < x)
            low = mid + 1;

        // If x is smaller, ignore right half
        else
            high = mid - 1;
    }

    // If we reach here, then element was
    // not present
    return -1;
}

// Driver code
public static void main(String args[])
{
    BinarySearch ob = new BinarySearch();
    int arr[] = { 2, 3, 4, 10, 40 };
    int n = arr.length;
    int x = 10;
    int result = ob.binarySearch(arr, x);
    if (result == -1)
        System.out.println(
            "Element is not present in array");
    else
        System.out.println("Element is present at "
                           + "index " + result);
}

}
`