Pagini recente » Cod sursa (job #3150791) | Cod sursa (job #2802246) | Cod sursa (job #1664080) | Hint 1 | Cod sursa (job #3154920)
#include <bits/stdc++.h>
using namespace std;
ifstream fin("2sat.in");
ofstream fout("2sat.out");
typedef pair<int,int> pii;
int n,m,use[300005],comp[300005],sol[300005];
vector<int> muchii[300005];
vector<int> nodes[300005];
int nr;
vector<pii> g;
vector<int> st;
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)
{
comp[nod]=nr;
nodes[nr].push_back(nod);
for(int i:muchii[nod])
if(comp[i]==0)
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);
muchii[-b+n].push_back(a+n);
g.push_back({-a+n,b+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=1;i<=n;i++)
{
muchii[-i+n].clear();
muchii[i+n].clear();
sol[-i+n]=-1;
sol[i+n]=-1;
}
for(auto i:g)
muchii[i.second].push_back(i.first);
for(int i:st)
if(comp[i]==0)
{
nr++;
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<=nr;i++)
{
int x=nodes[i][0];
if(sol[x]==-1)
{
for(int j:nodes[i])
{
int nod=j-n;
sol[j]=0;
sol[-nod+n]=1;
}
}
}
for(int i=1;i<=n;i++)
fout<<sol[i+n]<<' ';
return 0;
}