Cod sursa(job #3041370)

Utilizator BadHero112Ursu Vasile BadHero112 Data 31 martie 2023 13:21:50
Problema 2SAT Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.77 kb
#include <bits/stdc++.h>
using ll=long long;
#define S second
#define F first
#define endl '\n'
#define spid ios_base::sync_with_stdio(false);cin.tie(NULL);
const int mod=1e9+7;
const double pi=3.14159265359;
const int maxn=200005;
using namespace std;

int n,m,chk[maxn],ad[maxn];
vector<int> L;
vector<vector<int>> A(maxn,vector<int>()),inv(maxn,vector<int>());

void dfs1(int i){
	chk[i]=0;
	for(int j=0;j<A[i].size();j++){
		if(chk[A[i][j]])dfs1(A[i][j]);
	}
	L.push_back(i);
}

void dfs2(int i,int comp){
	chk[i]=comp;
	for(int j=0;j<inv[i].size();j++){
		if(chk[inv[i][j]]==0)dfs2(inv[i][j],comp);
	}
}

int main(){
	ifstream cin("2sat.in");
	ofstream cout("2sat.out");
	cin>>n>>m;
	for(int i=0;i<=2*n+1;i++)chk[i]=1;
	for(int i=0;i<m;i++){
		int a,b;
		cin>>a>>b;
		if(a<0&&b<0){
			A[2*(-a)].push_back(2*(-b)+1);
			inv[2*(-b)+1].push_back(2*(-a));
			A[2*(-b)].push_back(2*(-a)+1);
			inv[2*(-a)+1].push_back(2*(-b));
		}
		else if(a<0&&b>0){
			A[2*(-a)].push_back(2*b);
			inv[2*b].push_back(2*(-a));
			A[2*b+1].push_back(2*(-a)+1);
			inv[2*(-a)+1].push_back(2*b+1);
		}
		else if(b<0&&a>0){
			A[2*(-b)].push_back(2*a);
			inv[2*a].push_back(2*(-b));
			A[2*a+1].push_back(2*(-b)+1);
			inv[2*(-b)+1].push_back(2*a+1);
		}
		else{
			A[2*a+1].push_back(2*b);
			inv[2*b].push_back(2*a+1);
			A[2*b+1].push_back(2*a);
			inv[2*a].push_back(2*b+1);
		}
	}
	for(int i=2;i<=2*n+1;i++){
		if(chk[i])dfs1(i);
	}
	int comp=1;
	for(int i=L.size()-1;i>=0;i--){
		if(chk[L[i]]==0){
			dfs2(L[i],comp);
			comp++;
		}
	}
	int sw=1;
	for(int i=1;i<=n;i++){
		if(chk[2*i]==chk[2*i+1])sw=0;
		else if(chk[2*i]>chk[2*i+1])ad[i]=1;
		else ad[i]=0;
	}
	if(sw){
		for(int i=1;i<=n;i++)cout<<ad[i]<<" ";
	}
	else cout<<-1<<endl;
}