modified_binarysearch.txt

/*  my binarysearch will return last element  if target is greater than or equal to ending element and will
 return -1 if target is less than starting element else it will return index which is the last element smaller
 than equal to target     */
  ///////*******************LESS THAN EQUAL TO
//   end---->number of elements in vector


long int binarySearch(std::vector<long int> &arr,long int end, long int target)  
{  
    long int start = 0;  
    end--;
    long int ans = -1;  
    while (start <= end)  
    {  
        long int mid = (start + end) / 2;  
        if (arr[mid] > target) 
        {  
            end = mid - 1;  
        } 
        else 
        {  
            ans = mid;  
            start = mid + 1;  
        }  
    }  
    return ans;  
} 



/*  my binarysearch will return first element  if target is less than or equal to first element and will
 return -1 if target is greater than ending element else it will return index which is the first element greater
 than equal to target     */
//////////*******************GREATER THAN EQUAL TO
//   end----->number of elements in vector


long int binarySearch(std::vector<long int> &arr,long int end, long int target)  
{  
    long int start = 0; 
    end--;
    long int ans = -1; 
    while (start <= end) 
    { 
        long int mid = (start + end) / 2; 
        if (arr[mid] < target) 
            start = mid + 1; 
        else
        { 
            ans = mid; 
            end = mid - 1; 
        } 
    } 
    return ans;  
}