BinarySearch Algorithm

BinarySearch.cpp

/**
 *	@note: 
 *		Works properly with numbers. 
 *		other types may have to define another equality criteria.
 *
 *	@return: Item index if found. -1 otherwise.
 */
template<typename T>
int BinarySearch(T * arr, int size, T searchKey)
{
	int first = 0,
		last = size - 1,
		m = 0; // middle

	while (first <= last)
	{
		m = (first + last) / 2;
		
		if (arr[m] == searchKey)
		{
			return m;
		}
		else if (arr[m] < searchKey)
		{
			first = m + 1;
		}
		else
		{
			last = m - 1;
		}
	}
	return -1;
}