CF556B.Case of Fake Numbers

普及-

通过率:0%

时间限制:2.00s

内存限制:256MB

AC君温馨提醒

该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。

题目描述

Andrewid the Android is a galaxy-famous detective. He is now investigating a case of frauds who make fake copies of the famous Stolp's gears, puzzles that are as famous as the Rubik's cube once was.

Its most important components are a button and a line of n similar gears. Each gear has n teeth containing all numbers from 0 to n - 1 in the counter-clockwise order. When you push a button, the first gear rotates clockwise, then the second gear rotates counter-clockwise, the the third gear rotates clockwise an so on.

Besides, each gear has exactly one active tooth. When a gear turns, a new active tooth is the one following after the current active tooth according to the direction of the rotation. For example, if n = 5, and the active tooth is the one containing number 0, then clockwise rotation makes the tooth with number 1 active, or the counter-clockwise rotating makes the tooth number 4 active.

Andrewid remembers that the real puzzle has the following property: you can push the button multiple times in such a way that in the end the numbers on the active teeth of the gears from first to last form sequence 0, 1, 2, ..., n - 1. Write a program that determines whether the given puzzle is real or fake.

安卓侦探安德鲁伊德是银河系闻名的侦探。他目前正在调查一起造假案,涉案人员制造了著名斯托尔普齿轮谜题(Stolp's gears)的仿冒品——这种谜题的知名度曾堪比魔方。

该谜题最重要的组成部分是一个按钮和一排 nn 个完全相同的齿轮。每个齿轮有 nn 个齿,按逆时针顺序依次标有数字 00 到 n−1n-1。当你按下按钮时,第一个齿轮顺时针旋转,第二个齿轮逆时针旋转,第三个齿轮顺时针旋转,依此类推。

此外,每个齿轮恰好有一个“激活齿”(active tooth)。当齿轮转动时,新的激活齿即为当前激活齿沿旋转方向的下一个齿。例如,若 n=5n = 5,当前激活齿标号为 00,则顺时针旋转会使标号为 11 的齿变为激活齿,而逆时针旋转则会使标号为 44 的齿变为激活齿。

安德鲁伊德记得,真正的谜题具有如下性质:存在某种按按钮的次数(可多次),使得最终从第一个齿轮到第 nn 个齿轮的激活齿上的数字依次构成序列 0, 1, 2, …, n−10,\,1,\,2,\,\dots,\,n-1。请编写一个程序,判断给定的谜题是真品还是赝品。

输入格式

The first line contains integer n (1 ≤ n ≤ 1000) — the number of gears.

The second line contains n digits _a_1, _a_2, ..., a__n (0 ≤ a__i ≤ n - 1) — the sequence of active teeth: the active tooth of the i-th gear contains number a__i.

第一行包含一个整数 nn(1≤n≤10001 \leq n \leq 1000)——齿轮的数量。

第二行包含 nn 个数字 a1,a2,…,ana_1, a_2, \dots, a_n(0≤ai≤n−10 \leq a_i \leq n - 1)——活跃齿的序列:第 ii 个齿轮的活跃齿上标有数字 aia_i。

输出格式

In a single line print "Yes" (without the quotes), if the given Stolp's gears puzzle is real, and "No" (without the quotes) otherwise.

如果给定的斯托尔普齿轮谜题是真实的,则在一行中输出“Yes”(不带引号);否则输出“No”(不带引号)。

输入输出样例

  • 输入#1

    3
    1 0 0

    输出#1

    Yes
  • 输入#2

    5
    4 2 1 4 3

    输出#2

    Yes
  • 输入#3

    4
    0 2 3 1

    输出#3

    No

说明/提示

In the first sample test when you push the button for the first time, the sequence of active teeth will be 2 2 1, when you push it for the second time, you get 0 1 2.

在第一个样例测试中,当你第一次按下按钮时,活动齿的序列为 2 2 12\ 2\ 1;当你第二次按下按钮时,得到 0 1 20\ 1\ 2。

输入解题思路,AI测评打分。不知道怎么写?

首页