[C++知识库](个人纪录) Codeforces Round #779 (Div. 2) C. Shinju and the Lost Permutation

原题链接

#include <bits/stdc++.h>
//#include <关注嘉然然，顿顿解馋馋>
using namespace std;

#define io ios::sync_with_stdio(0);cin.tie(0)
#define LL long long
#define PII pair<int, int> 
#define PLL pair<LL, LL>
#define fi first
#define se second
const int N = 1e5 + 10;
const int INF = 0x3f3f3f3f;
const int mod = 998244353;

string solve() {
	int n; cin >> n;
	vector<int> a(n);
	for(auto &v : a)
		cin >> v;
	if(count(a.begin(), a.end(), 1) != 1)
		return "NO";
	
	int p = find(a.begin(), a.end(), 1) - a.begin();
	rotate(a.begin(), a.begin() + p, a.end());
	for(int i = 1; i < n; i ++) {
		if(a[i] - a[i-1] > 1)
			return "NO";
	}
	
	return "YES";
}

int main() {
	int T; cin >> T;
	while(T --) {
		cout << solve() << endl;
	}
	return 0;
}


/*
    像是6.02×1023个微粒一样 
*/