Online JudgeProblem SetAuthorsOnline ContestsUser
Web Board
Home Page
F.A.Qs
Statistical Charts
Problems
Submit Problem
Online Status
Prob.ID:
Register
Update your info
Authors ranklist
 Current Contest
Past Contests
Scheduled Contests
Award Contest
User ID:
Password:
  Register

给新手解释下答案

Posted by fbixiaozc135 at 2007-07-16 20:30:30 on Problem 3210 
 因为当coins全部同向时，最后要同向必然要翻转偶数次，所以若有偶数个coins时，若只有一个跟其他的反向时，必要翻转奇数次以达到目的。这两种情况矛盾，所以，偶数时题无解，对于奇数个coin，可由数学归纳法得到结果。
Followed by:
Post your reply here:
User ID:
Password:
Title:

Content:

Home Page   Go Back  To top

All Rights Reserved 2003-2013 Ying Fuchen,Xu Pengcheng,Xie Di
Any problem, Please Contact Administrator