#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("Ofast,unroll-loops")
using namespace std;
using namespace __gnu_pbds;
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define f first
#define s second
#define int long long
#define pii pair<int,int>
template<class T>bool umax(T &a,T b){if(a<b){a=b;return true;}return false;}
template<class T>bool umin(T &a,T b){if(b<a){a=b;return true;}return false;}
typedef tree<int, null_type, less_equal<int>, rb_tree_tag,
tree_order_statistics_node_update> ordered_set;
const int inf = 1e17 + 7;
const int mod = 1e9 + 7;
const int N = 3e5 + 5;
const int md = 998244353;
int binpow(int a, int b){
if(b == 0)return 1;
if(b % 2 == 0){
int c = binpow(a,b/2);
return (c*c)%mod;
}
return (binpow(a,b-1)*a)%mod;
}
int divi(int a, int b){
return (a*(binpow(b,mod-2)))%mod;
}
int n,m,k;
void solve(){
cin >> n;
vector<int>v(n);
for(auto &to:v)cin >> to;
vector<int>ans;
for(int i = 0;i<n;i++){
vector<int>vis(n), vs(n);
vis[v[i]] = 1;
vs[i] = v[i];
bool flag = true;
for(int j = 0;j<n;j++){
if(j == i)continue;
if(vis[j+1] == 0){
vis[j+1] = 1;
vs[j] = j+1;
}
else if(vis[v[j]] == 0){
vis[v[j]] = 1;
vs[j] = v[j];
}
else flag = false;
}
if(!flag)continue;
for(int j = 0;j<n;j++){
if(vs[j] != v[j])flag = false;
}
if(!flag)continue;
ans.pb(i+1);
}
//~ cout << ans.size() << " ";
//~ for(auto to:ans)cout << to << " ";
//~ cout << "\n";
if(ans.size() != 1)cout << 0 << "\n";
else cout << ans[0] << "\n";
}
/*
2
2
2 1
4
4 2 3 1 4
*/
signed main()
{
// freopen("seq.in", "r", stdin);
// freopen("seq.out", "w", stdout);
ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
int tt=1;cin>>tt;
while(tt--)solve();
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
348 KB |
Output is correct |
| 2 |
Runtime error |
1 ms |
604 KB |
Execution killed with signal 6 |
| 3 |
Halted |
0 ms |
0 KB |
- |
