If devide-and-conquer strategy is used to find the closest pair

If devide-and-conquer strategy is used to find the closest pair of points in a plane, unless the points are sorted not only by their $$x$$ coordinates but also by their $$y$$ coordinates, it would be impossible to solve it in a time of $$O(NlogN)$$, where $$N$$ is the number of points. ~@[](2)

答案：TRUE