CF1203A.Circle of Students
普及/提高-
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题目描述
There are n students standing in a circle in some order. The index of the i -th student is pi . It is guaranteed that all indices of students are distinct integers from 1 to n (i. e. they form a permutation).
Students want to start a round dance. A clockwise round dance can be started if the student 2 comes right after the student 1 in clockwise order (there are no students between them), the student 3 comes right after the student 2 in clockwise order, and so on, and the student n comes right after the student n−1 in clockwise order. A counterclockwise round dance is almost the same thing — the only difference is that the student i should be right after the student i−1 in counterclockwise order (this condition should be met for every i from 2 to n ).
For example, if the indices of students listed in clockwise order are [2,3,4,5,1] , then they can start a clockwise round dance. If the students have indices [3,2,1,4] in clockwise order, then they can start a counterclockwise round dance.
Your task is to determine whether it is possible to start a round dance. Note that the students cannot change their positions before starting the dance; they cannot swap or leave the circle, and no other student can enter the circle.
You have to answer q independent queries.
输入格式
The first line of the input contains one integer q ( 1≤q≤200 ) — the number of queries. Then q queries follow.
The first line of the query contains one integer n ( 1≤n≤200 ) — the number of students.
The second line of the query contains a permutation of indices p1,p2,…,pn ( 1≤pi≤n ), where pi is the index of the i -th student (in clockwise order). It is guaranteed that all pi are distinct integers from 1 to n (i. e. they form a permutation).
输出格式
For each query, print the answer on it. If a round dance can be started with the given order of students, print "YES". Otherwise print "NO".
输入输出样例
输入#1
5 4 1 2 3 4 3 1 3 2 5 1 2 3 5 4 1 1 5 3 2 1 5 4
输出#1
YES YES NO YES YES