Reverse a Permutation

    1#include <bits/stdc++.h>
    2using namespace std;
    3typedef long long ll;
    4const int inf = 1e9;
    5const long long INF = 1e17; //❄️
    6void solve() {
    7    int n; cin >> n;
    8    vector<int> p(n);
    9    for (int i = 0; i < n; i++) {
    10        cin >> p[i];
    11    }
    12    int end = -1;
    13    for (int i = 0; i < n; i++) {
    14        if (p[i] != n - i) {
    15            end = i; break;
    16        }
    17    }
    18    if (end == -1) {
    19        for (int i = 0; i < n; i++) {
    20            cout << n - i << " \n"[i == n - 1];
    21        }
    22        return;
    23    }
    24    int start = find(p.begin(), p.end(), n - end) - p.begin();
    25    for (int i = 0; i < end; i++) {
    26        cout << p[i] << " ";
    27    }
    28    for (int i = start; i >= end; i--) {
    29        cout << p[i] << " ";
    30    }
    31    for (int i = start + 1; i < n; i++) {
    32        cout << p[i] << " ";
    33    }
    34    cout << '\n';
    35}
    36int main() {
    37    ios::sync_with_stdio(0); cin.tie(0); 
    38    int t; cin >> t;
    39    while (t--) {
    40        solve();
    41    }
    42    return 0;
    43}