42 lines
905 B
C++
42 lines
905 B
C++
|
#include<bits/stdc++.h>
|
||
|
|
using namespace std;
|
||
|
|
#ifdef ONLINE_JUDGE
|
||
|
|
#define dbg(...)
|
||
|
|
#else
|
||
|
|
#include "debug.h"
|
||
|
|
#endif
|
||
|
|
#define ll long long
|
||
|
|
#define endl '\n'
|
||
|
|
#define all(x) x.begin(), x.end()
|
||
|
|
#define sz(x) (int)(x).size()
|
||
|
|
#define yes cout<<"YES"<<endl
|
||
|
|
#define no cout<<"NO"<<endl
|
||
|
|
#define FAST (ios_base:: sync_with_stdio(false),cin.tie(NULL));
|
||
|
|
ll pow(ll x,ll y,ll m=1e9+7){ll ans=1;x%=m;while(y){if(y&1)ans=(ans*x)%m;x=(x*x)%m;y>>=1;}return ans;}
|
||
|
|
|
||
|
|
void solve()
|
||
|
|
{
|
||
|
|
int n;
|
||
|
|
cin>>n;
|
||
|
|
vector<int>v(n);
|
||
|
|
for(auto &i:v) cin>>i;
|
||
|
|
for(int i=0; i<n; ++i)
|
||
|
|
{
|
||
|
|
int fnd=i+1;
|
||
|
|
int bst=v[i];
|
||
|
|
if(v[bst-1]==fnd)
|
||
|
|
{
|
||
|
|
cout<<2<<endl;
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
cout<<3<<endl;
|
||
|
|
}
|
||
|
|
|
||
|
|
signed main()
|
||
|
|
{
|
||
|
|
FAST;
|
||
|
|
int TC = 1;
|
||
|
|
cin >> TC;
|
||
|
|
while (TC--) solve();
|
||
|
|
}
|