bool binary_search(const int *a, int n, int v)
{
int low = 0;
	int high = n;
	int mid;
	int found = 0;

	while(low <= high && found == 0)
	{
		mid = (high + low)/2;
		if(a[mid] == v)
			found = 1;
		else if(a[mid] > v)
			high = mid - 1;
		else
			low = mid + 1;
	}

	if(found == 1)
		return true;
	else
		return false;
}