题解 | 有序序列判断（最短的写法）

#include <bits/stdc++.h>

using namespace std;

signed main() {
    int n;
    cin >> n;
    vector<int> a(n);
    for (int i = 0; i < n; i++) cin >> a[i];
    vector<int> b = a;
    reverse(b.begin(), b.end());
    if (is_sorted(a.begin(), a.end()) || is_sorted(b.begin(), b.end())) puts("sorted");
    else puts("unsorted");
    return 0;
}