//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//#pragma GCC optimize("Ofast,unroll-loops,fast-math,O3")
#include<bits/stdc++.h>
using namespace std;
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define sz(a) (int)a.size()
#define pf push_front
#define pb push_back
#define vt vector
#define s second
#define f first
#define nl '\n'
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
vt<pii> rid = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};
vt<pii> dir = {{-1, -1}, {-1, 1}, {1, -1}, {1, 1}};
const int N = 1e5, mod = 998244353;
const ll inf = 1e9;
double eps = 1e-15;
bool fl = 1;
void slv() {
int n;
cin >> n;
int p[n + 1];
for (int i = 1; i <= n; i++) cin >> p[i];
int cnt = 0, ans = 0;
for (int x = 1; x <= n; x++) {
vt<bool> was(n + 1);
was[p[1]] = 1;
bool ok = 1;
for (int i = 1, j = 2; i <= n; i++) {
if (i == x) continue;
if (!was[i]) {
if (p[j] != i) {
ok = 0;
break;
}
was[i] = 1;
}else {
if (was[p[j]]) {
ok = 0;
break;
}
was[p[j]] = 1;
}
j++;
}
if (ok) {
if (cnt == 1) {
cout << 0 << nl;
return;
}
cnt++;
ans = x;
}
}
cout << ans << nl;
}
main() {
//freopen("shops.in", "r", stdin);
//freopen("shops.out", "w", stdout);
ios_base::sync_with_stdio(0);
cin.tie(0);
int tp = 1;
if (fl) cin >> tp;
while (tp--) {
slv();
}
}
Compilation message
crazy.cpp:74:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
74 | main() {
| ^~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
328 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
212 KB |
Output is correct |
7 |
Correct |
1 ms |
212 KB |
Output is correct |
8 |
Correct |
2 ms |
332 KB |
Output is correct |
9 |
Correct |
2 ms |
212 KB |
Output is correct |
10 |
Correct |
2 ms |
340 KB |
Output is correct |
11 |
Correct |
2 ms |
340 KB |
Output is correct |
12 |
Correct |
2 ms |
340 KB |
Output is correct |
13 |
Correct |
2 ms |
340 KB |
Output is correct |
14 |
Correct |
3 ms |
340 KB |
Output is correct |
15 |
Correct |
5 ms |
344 KB |
Output is correct |
16 |
Correct |
6 ms |
348 KB |
Output is correct |
17 |
Correct |
6 ms |
340 KB |
Output is correct |
18 |
Correct |
8 ms |
340 KB |
Output is correct |
19 |
Correct |
7 ms |
340 KB |
Output is correct |
20 |
Correct |
10 ms |
368 KB |
Output is correct |