Binary Search in C++ (Arrays Part)

 #include<iostream>

using namespace std;

int binSearch(int *arr, int n, int key) {

    int st = 0, end = n-1;

    while(st <= end) {

        int mid = (st + end) / 2;

        if(arr[mid] == key) {

            return mid; // key found

        } else if(arr[mid] < key) { // 2nd half search

            st = mid + 1;

        } else {

            // 1st half

            end = mid-1;

        }

    }

    return -1;

}

int main(){

    int arr[] = {2, 4, 6, 8, 10, 12, 14, 16};

    int n = sizeof(arr) / sizeof(int);

    cout << binSearch(arr, n, 4) << endl;

    return 0;

}

OUTPUT-

1