Cod sursa(job #2518199)

Utilizator vic2002Melinceanu Victor vic2002 Data 5 ianuarie 2020 12:31:28
Problema 2SAT Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.45 kb
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#define rc(x) return cout<<x<<endl,0
#define pb push_back
#define mkp make_pair
#define in insert
#define er erase
#define fd find
#define fr first
#define sc second
typedef long long ll;
typedef long double ld;
const ll INF=0x3f3f3f3f3f3f3f3f;
const ll llinf=(1LL<<62);
const int inf=(1<<30);
const int nmax=2e5+50;
const int mod=1e9+7;
using namespace std;
int n,m,i,x,y,col[nmax],v[nmax],c,rs[nmax];
vector<int>g[nmax],rg[nmax],ord;
int tr(int x)
{
	if(x<0)return -2*x-1;
	return 2*x;
}
void dfs1(int x)
{
	v[x]=1;
	for(int i=0;i<(int)g[x].size();i++)if(!v[g[x][i]])dfs1(g[x][i]);
	ord.pb(x);
}
void dfs2(int x)
{
	col[x]=c;
	for(int i=0;i<(int)rg[x].size();i++)if(!col[rg[x][i]])dfs2(rg[x][i]);
}
int main()
{
	freopen("2sat.in","r",stdin);
	freopen("2sat.out","w",stdout);
	//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
	ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
	cin>>n>>m;
	while(m--)
	{
		cin>>x>>y;
		g[tr(-x)].pb(tr(y));
		g[tr(-y)].pb(tr(x));
		rg[tr(y)].pb(tr(-x));
		rg[tr(x)].pb(tr(-y));
	}
	for(i=1;i<=2*n;i++)
	{
		if(v[i])continue;
		dfs1(i);
	}
	reverse(ord.begin(),ord.end());
	for(i=0;i<2*n;i++)
	{
		if(col[ord[i]])continue;
		c++;
		dfs2(ord[i]);
	}
	for(i=2;i<=2*n;i+=2)
	{
		if(col[i]==col[i-1])rc(-1);
		rs[i/2]=(col[i]>col[i-1]);
	}
	for(i=1;i<=n;i++)cout<<rs[i]<<' ';
	cout<<endl;
	return 0;
}