摘要：You are given a set of nn points in a 2D plane. No three points are collinear. A pentagram is a set of 55 points A,B,C,D,EA,B,C,D,E that can be arrang 阅读全文

摘要：Vasya likes to travel by train, but doesn't like when the car he travels in is located in the tail of the train. Vasya gets on the train at the statio 阅读全文