在二维空间里有两个点A=(X1，Y1)和B=(X2，Y2)，如果X1>X2并且Y1>Y2 ，我们认为A优于B，A是这个集合的最大极值点，在给定的二维空间里的N个点的集合S中，找出最大极值点。,In a two-dimensional space, there are two points A = (X1, Y1) and B = (X2, Y2), if X1>　X2, and Y1>　Y2, we believe that A is better than B, A is the collection of the maximum extreme point N points in the two-dimensional space in a given set S, find the maximum extreme point.