Binary Search (GFG)

Given a sorted array of size N and an integer K, find the position at which K is present in the array using binary search.

---

STUDYEVERTHING

---

// { Driver Code Starts

// Initial template for C++

#include <bits/stdc++.h>

using namespace std;

 // } Driver Code Ends

// User function template for C++

class Solution {

  public:

    long long int binarysearch(int arr[], int n, int k) {

    long long int l = 0, r = n - 1, mid, ans;

    while (l <= r)

    {

        mid = (r - l) / 2 + l;

        if (arr[mid] == k)

        {

            ans = mid;

            l = n;

        }

        else if (arr[mid] > k) 

        {

            r--;

        }

        else

        {

            l++;

        }

    }

     int ans2=-1;

    if(ans == mid){

          ans2 = ans;

    }

     return ans2;}

};

// { Driver Code Starts.

int main() {

    int t;

    cin >> t;

    while (t--) {

        int N;

        cin >> N;

        int arr[N];

        for (int i = 0; i < N; i++) cin >> arr[i];

        int key;

        cin >> key;

        Solution ob;

        int found = ob.binarysearch(arr, N, key);

        cout << found << endl;

    }

}

  // } Driver Code Ends

Happy Coding 😊.