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Cod sursa(job #383828)
#include <stdio.h>
#include <vector>
#include <cstring>
using namespace std;
#define maxn 200100
#define pb push_back
long n, m, i, j, k, nod, sol, a, b, f[maxn], st[maxn], st2[maxn], u[maxn], cul[maxn];
vector<long> v[maxn], vi[maxn], vc[maxn];
void df(long nod)
{
if(f[nod]) return;
long y;
f[nod]=1;
for(y=0; y<v[nod].size(); y++)
df(v[nod][y]);
st[++st[0]]=nod;
}
void df2(long nod, long who)
{
if(f[nod]) return;
long y=0;
f[nod]=1;
u[nod]=who;
for(y=0; y<vi[nod].size(); y++)
df2(vi[nod][y], who);
st2[++st2[0]]=nod;
}
int main()
{
freopen("2sat.in", "r", stdin);
freopen("2sat.out", "w", stdout);
scanf("%d%d", &n, &m);
for(i=1; i<=m; i++)
{
scanf("%d%d", &a, &b);
if(a<0) a=-a+n;
if(b<0) b=-b+n;
--a;
--b;
v[(a+n)%(2*n)].pb(b);
v[(b+n)%(2*n)].pb(a);
vi[b].pb((a+n)%(2*n));
vi[a].pb((b+n)%(2*n));
}
for(i=0; i<2*n; i++)
if(!f[i])
df(i);
memset(f, 0, sizeof(f));
for(i=2*n; i; --i)
{
cul[i-1]=2;
if(!f[st[i]])
{
df2(st[i], st[i]);
sol++;
}
}
for(i=2*n; i; --i)
{
nod=st[i];
if(cul[u[nod]]==2)
{
cul[u[nod]]=0;
if(cul[u[(nod+n)%(2*n)]]!=2)
{
printf("-1\n");
return 0;
}
cul[u[(nod+n)%(2*n)]]=1;
}
}
for(i=0; i<n; i++)
printf("%d ", cul[u[i]]);
printf("\n");
return 0;
}