Question

1.6 code practice question 2 edhesive answer

Answer 1

// C++ program to implement recursive Binary Search

#include <bits/stdc++.h>

using namespace std;

// A recursive binary search function. It returns

// location of x in given array arr[l..r] is present,

// otherwise -1

int binarySearch(int arr[], int l, int r, int x)

{

if (r >= l) {

int mid = l + (r - l) / 2;

// If the element is present at the middle

// itself

if (arr[mid] == x)

return mid;

// If element is smaller than mid, then

// it can only be present in left subarray

if (arr[mid] > x)

return binarySearch(arr, l, mid - 1, x);

// Else the element can only be present

// in right subarray

return binarySearch(arr, mid + 1, r, x);

}

// We reach here when element is not

// present in array

return -1;

}

int main(void)

{

int arr[] = { 2, 3, 4, 10, 40 };

int x = 10;

int n = sizeof(arr) / sizeof(arr[0]);

int result = binarySearch(arr, 0, n - 1, x);

(result == -1) ? cout << "Element is not present in array"

: cout << "Element is present at index " << result;

return 0;

}