Pagini recente » Cod sursa (job #707070) | Cod sursa (job #2773946) | Cod sursa (job #21214) | Cod sursa (job #27890) | Cod sursa (job #3208106)
#include <bits/stdc++.h>
using namespace std;
ifstream fin("2sat.in");
ofstream fout("2sat.out");
typedef pair<int,int> pii;
bool use[200005];
int n,m,comp[200005],sol[200005];
vector<int> st;
vector<int> muchii[200005];
vector<pii> g;
int nrcomp;
vector<int> who[200005];
void dfs1(int nod)
{
use[nod]=1;
for(int i:muchii[nod])
if(!use[i])
dfs1(i);
st.push_back(nod);
}
void dfs2(int nod)
{
who[nrcomp].push_back(nod);
comp[nod]=nrcomp;
for(int i:muchii[nod])
if(!comp[i])
dfs2(i);
}
int main()
{
ios_base::sync_with_stdio(false);
fin.tie(0);
fin>>n>>m;
for(int i=1;i<=m;i++)
{
int a,b;
fin>>a>>b;
muchii[-a+n].push_back(b+n);
g.push_back({-a+n,b+n});
muchii[-b+n].push_back(a+n);
g.push_back({-b+n,a+n});
}
for(int i=1;i<=n;i++)
{
if(!use[i+n])
dfs1(i+n);
if(!use[-i+n])
dfs1(-i+n);
}
reverse(st.begin(),st.end());
for(int i=0;i<=2*n;i++)
{
use[i]=0;
muchii[i].clear();
}
for(auto i:g)
muchii[i.second].push_back(i.first);
for(int i:st)
if(!comp[i])
{
nrcomp++;
dfs2(i);
}
for(int i=1;i<=n;i++)
if(comp[i+n]==comp[-i+n])
{
fout<<-1;
return 0;
}
for(int i=1;i<=nrcomp;i++)
{
bool go=1;
for(int j:who[i])
if(use[j])
go=0;
if(!go)
continue;
for(int j:who[i])
{
int x=j-n;
if(x>0)
sol[x]=0;
else
sol[abs(x)]=1;
use[j]=1;
use[-x+n]=1;
}
}
for(int i=1;i<=n;i++)
fout<<sol[i]<<' ';
return 0;
}