Binary search on an array of integer without using Recurssion :

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This will execute in O(log(N)) time where N is the size of array and it will use constant space size ,but binary search with recursion uses O(log(N)) stack size. the code

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#include <iostream>

using namespace std;

int main() 

{

  

 int a[] = {1,2,3,4,5,6,7,8,9,10,11,12,13,14};

 

 int n = sizeof(a)/sizeof(a[0]);

 int i = 0;

 int j = n-1;

 int x=12,f=0;

 

  while(i<=j)

   {

     if(i==j && a[i] == x)

     {

     cout<< " found " <<a[i] << " at " <<i;

     f =1;

     return 0;

     }

     

     int mid = (i+j)/2;

     

     if(a[mid]  == x)

     {

     cout << " found " <<a[mid] << " at " <<mid;

     f=1;

     return 0;

     }

     if(x < a[mid]) 

     j = mid - 1;

     else 

     i = mid + 1 ;

    }

    if( f==0)

    cout<<"not present";

 

 

}