diff --git a/binary_search/binary_search.cpp b/binary_search/binary_search.cpp new file mode 100644 index 00000000..452354ee --- /dev/null +++ b/binary_search/binary_search.cpp @@ -0,0 +1,42 @@ +// C++ program to implement recursive Binary Search +#include +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; +}