摘要：
Problem Statement You are given two integer sequences, each of length N: a1,…,aN and b1,…,bN. There are N2 ways to choose two integers i and j such th 阅读全文
摘要：
Problem Statement On a two-dimensional plane, there are N red points and N blue points. The coordinates of the i-th red point are (ai,bi), and the coo 阅读全文