Submission #1867058

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Source Code Expand

#include"bits/stdc++.h"


#define PB push_back
#define PF push_front
#define LB lower_bound
#define UB upper_bound
#define fr(x) freopen(x,"r",stdin)
#define fw(x) freopen(x,"w",stdout)
#define iout(x) printf("%d\n",x)
#define lout(x) printf("%lld\n",x)
#define REP(x,l,u) for(int x = (l);x<=(u);x++)
#define RREP(x,l,u) for(int x = (l);x>=(u);x--)
#define mst(x,a) memset(x,a,sizeof(x))
#define PII pair<int,int>
#define PLL pair<ll,ll>
#define MP make_pair
#define se second
#define fi first
#define dbg(x) cout<<#x<<" = "<<(x)<<endl;
#define sz(x) ((int)x.size())
#define cl(x) x.clear()

typedef  long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ld;
using namespace std;

const int maxn = 600010;
const int mod = 1e9+7;
const int MAX = 1000000010;
const double eps = 1e-6;
const double PI = acos(-1);

template<typename T> inline void read(T &x){
x=0;T f=1;char ch;do{ch=getchar();if(ch=='-')f=-1;}while(ch<'0'||ch>'9');do x=x*10+ch-'0',ch=getchar();while(ch<='9'&&ch>='0');x*=f;
}

template<typename A,typename B> inline void read(A&x,B&y){read(x);read(y);}
template<typename A,typename B,typename C> inline void read(A&x,B&y,C&z){read(x);read(y);read(z);}
template<typename A,typename B,typename C,typename D> inline void read(A&x,B&y,C&z,D&w){read(x);read(y);read(z);read(w);}
template<typename A,typename B> inline A fexp(A x,B p){A ans=1;for(;p;p>>=1,x=1LL*x*x%mod)if(p&1)ans=1LL*ans*x%mod;return ans;}
template<typename A,typename B> inline A fexp(A x,B p,A mo){A ans=1;for(;p;p>>=1,x=1LL*x*x%mo)if(p&1)ans=1LL*ans*x%mo;return ans;}

int n,rt1,rt2;

int fa[maxn];

vector<int> G[maxn];

int f[maxn],Ans[maxn],S[maxn],top;

map<PII,int> mp;

int cur[maxn];

void Euler(int u){
	for(int &i=cur[u];i<G[u].size();i++){
		int v=G[u][i];
		if(!mp[MP(u,v)]){
			mp[MP(v,u)]=mp[MP(u,v)]=1;
			Euler(v);
		}
	}
	S[++top]=u;
}

void dfs(int u){
	f[u]=1;
	for(auto v:G[u])if(v!=fa[u])dfs(v),f[u]^=1;
}

void Work(){
	dfs(rt1);
	dfs(rt2);
	REP(i,1,n)if(f[i]!=f[i+n]){
		puts("IMPOSSIBLE");
		return;
	}
	puts("POSSIBLE");
	REP(i,1,n)if(f[i])G[i].PB(i+n),G[i+n].PB(i),Ans[i]=-1;
	G[0].PB(rt1);G[rt1].PB(0);
	G[0].PB(rt2);G[rt2].PB(0);
	Euler(0);
	REP(i,1,top-1)if(S[i+1]==S[i]+n)Ans[S[i]]=1;
	REP(i,1,n)printf("%d ",Ans[i]);puts("");
}

void Init(){
	read(n);
	REP(i,1,n){
		read(fa[i]);
		if(fa[i]==-1)rt1=i;
		else G[i].PB(fa[i]),G[fa[i]].PB(i);
	}
	REP(i,n+1,n*2){
		read(fa[i]);
		if(fa[i]==-1)rt2=i;
		else fa[i]+=n,G[i].PB(fa[i]),G[fa[i]].PB(i);
	}
}

int main(){
	Init();
	Work();
	return 0;
}

Submission Info

Judge Result