Submission #10182819

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
int hmt() {int x=0;int c=getchar(),n=0;for(;!isdigit(c);c=getchar()) n=(c=='-');for(;isdigit(c);c=getchar()) x=x*10+c-'0';if(n) x=-x;return x;}
#define in hmt()
#define ins ({string x;char c=getchar();for(;c==' '||c=='\n';c=getchar());for(;c!=' '&&c!='\n';c=getchar()) x+=c;x;})
#define forinc(i,a,b) for(int i=a,_b=b;i<=_b;++i)
#define fordec(i,a,b) for(int i=a;i>=b;--i)
#define forb(i,BS) for(int i=BS._Find_first();i< BS.size();i = BS._Find_next(i))
#define forv(a,b) for(auto &a:b)
#define pb push_back
#define pii pair<int,int>
#define fi first
#define se second
#define all(a) a.begin(),a.end()
#define reset(f,x) memset(f,x,sizeof(f))
#define bit(x,i) ((x>>(i-1))&1)
#define onbit(x,i) (x|(1<<(i-1)))
#define offbit(x,i) (x&~(1<<(i-1)))
const int N=100010;
int n,x[N],s[N],a[N];
set<int> f;
set<pii> t;
void duyet(int i,int p)
{
    if(i==n+1)
    {
        forinc(j,1,n) cout<<x[j]<<" ";
        exit(0);
    }
    if(t.rbegin()->fi==n-i)
    {
        int u=t.rbegin()->se;
        x[i]=u;
        f.erase(u);
        t.erase({s[u],u});
        t.erase({s[a[u]],a[u]});
        s[a[u]]--;
        t.insert({s[a[u]],a[u]});
        duyet(i+1,u);
        f.insert(u);
        t.erase({s[a[u]],a[u]});
        s[a[u]]++;
        t.insert({s[u],u});
        t.insert({s[a[u]],a[u]});
    }
    else
    {
        forv(u,f) if(a[p]!=u)
        {
            x[i]=u;
            f.erase(u);
            t.erase({s[u],u});
            t.erase({s[a[u]],a[u]});
            s[a[u]]--;
            t.insert({s[a[u]],a[u]});
            duyet(i+1,u);
            f.insert(u);
            t.erase({s[a[u]],a[u]});
            s[a[u]]++;
            t.insert({s[u],u});
            t.insert({s[a[u]],a[u]});
        }
    }
}
int main()
{
    //freopen("ATCODER.inp","r",stdin);
    n=in;
    forinc(i,1,n) a[i]=in,f.insert(i),s[a[i]]++;
    forinc(i,1,n) t.insert({s[i],i});
    if(n==2&&a[1]==2) return cout<<-1,0;
    duyet(1,0);
}

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