Round#579(Div 3) A. Circle of Students

The meaning of problems: inputting a set of numbers from 1 to n, it is determined whether it can constitute a valid ring

ps: legal cycloalkyl refers 1,2,3,4 ,,,, n or n, n - 1 ,,,, end to end ring 2 consisting of - 1, n

Ideas: The number of input connected end to end of the original array, violent searches whether a length of n, and continuously rising or continuously falling substring

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 const int maxn = 201*5;
 4 int a[maxn];
 5 int main() {
 6     int q;
 7     cin>>q;
 8     while(q --){
 9         int n;
10         cin>>n;
11         for(int i = 0; i < n; i ++){
12             int inp;
13             cin>>inp;
14             a[i] = a[i + n] = a[i + 2*n] = inp;
15         }
16         bool ans = false;
17         for(int i = 0; i < 3*n; i ++){
18             int cnt = 1;
19             int ptr = i + 1;
20             while(a[ptr] > a[ptr - 1] && ptr < 3*n){
21                 cnt ++;
22                 ptr ++;
23             }
24             if(cnt >= n){
25                 ans = true;
26                 break;
27             }
28             cnt = 1;
29             ptr = i + 1;
30             while(a[ptr] < a[ptr - 1] && ptr < 3*n){
31                 cnt ++;
32                 ptr ++;
33             }
34             if(cnt >= n){
35                 ans = true;
36                 break;
37             }
38         }
39         if(ans){
40             cout<<"YES"<<endl;
41         }else {
42             cout<<"NO"<<endl;
43         }
44     }
45     return 0;
46 }