Search recursive-BINARY SEARCH

#include<iostream>

using namespace std;

///binary search using recursion...

int binarysearch(int *a,int no,int i,int n){

    if(i<n){

        int mid=(i+n)/2;

        if(a[mid]==no){

            return 1;

        }

        else if(no<a[mid]){

            return binarysearch(a,no,0,mid-1);

        }

        else if(no>a[mid]){

            return binarysearch(a,no,mid+1,n);

        }

    }

    return 0;

}

int main()

{

    int *a,n,no;

    cout<<"enter no of elements in an array";

    cin>>n;

    a=new int[n];

    ///getting array elements

    ///important condition :: the array should be in sorted order to perform binary search..

    for(int i=0;i<n;i++){

        cin>>a[i];

    }

    cout<<"enter the element to be searched";

    cin>>no;

    ///call binary search function

    if(binarysearch(a,no,0,n)){

        cout<<"FOUND\n";

    }

    else{

        cout<<"NOT FOUND\n";

    }

    return 0;
}

TIME COMPLEXITY:
        O(log n)


Next-Binary Search-Iterative