Submission #1440540

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;
using ll=long long;
#define int ll
#define FOR(i,a,b) for(int i=int(a);i<int(b);i++)	
#define REP(i,b) FOR(i,0,b)
int read(){
	int i;
	scanf("%lld",&i);
	return i;
}
using vi=vector<int>;
#define PB push_back
#define ALL(x) x.begin(),x.end()
using pi=pair<int,int>;

void chmin(int&a,int b){
	a=a<b?a:b;
}
void chmax(int&a,int b){
	a=a>b?a:b;
}

const int Nmax=114514;

vi g[Nmax];
void AddEdge(int a,int b){
	g[a].PB(b);
	g[b].PB(a);
}
bool vis[Nmax];
int ans[Nmax];
void dfs2(int v,int d){
	if(vis[v])return;
	vis[v]=true;
	ans[v]=d;
	for(auto to:g[v])
		dfs2(to,-d);
}

vi t[2][Nmax];
int dfs(int v,int k){
	int res=-1;
	for(auto ch:t[k][v]){
		int w=dfs(ch,k);
		if(res==-1)
			res=w;
		else{
			AddEdge(res,w);
			res=-1;
		}
	}
	if(res==-1)res=v;
	return res;
}

signed main(){
	int n=read(),root[2];
	REP(k,2)
		REP(i,n){
			int p=read();
			if(p==-1)root[k]=i;
			else t[k][p-1].PB(i);
		}
	REP(i,n)
		if(int(t[0][i].size())%2!=int(t[1][i].size())%2){
			cout<<"IMPOSSIBLE"<<endl;
			return 0;
		}
	REP(k,2)
		dfs(root[k],k);
	REP(i,n)
		if(int(t[0][i].size())%2==0&&!vis[i])
			dfs2(i,1);
	cout<<"POSSIBLE"<<endl;
	REP(i,n)
		printf(i<n-1?"%lld ":"%lld\n",ans[i]);
}

Submission Info

Compile Error

./Main.cpp: In function ‘ll read()’:
./Main.cpp:9:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld",&i);
                  ^

Judge Result