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Cod sursa(job #384175)
#include <cstdio>
#include <cstring>
#include <vector>
using namespace std;
const int MAX_N = 100005;
int n, m;
vector<int> G[2 * MAX_N], G2[2 * MAX_N];
int st[2 * MAX_N];
bool viz[2 * MAX_N];
bool value[2 * MAX_N], no_sol;
inline int neg(int val) { return val > n ? val - n : val + n; }
void df(int nod) {
viz[nod] = true;
for (vector<int>::iterator it = G[nod].begin(); it != G[nod].end(); ++it)
if (!viz[*it]) df(*it);
st[++st[0]] = nod;
}
void df2(int nod) {
if (value[nod]) no_sol = true;
viz[nod] = viz[neg(nod)] = true;
value[neg(nod)] = true;
for (vector<int>::iterator it = G2[nod].begin(); it != G2[nod].end(); ++it)
if (!viz[*it]) df2(*it);
}
int main() {
freopen("2sat.in", "r", stdin);
freopen("2sat.out", "w", stdout);
scanf("%d %d", &n, &m);
for (int i = 0; i < m; ++i) {
int a, b;
scanf("%d %d", &a, &b);
if (a < 0) a = (-a) + n;
if (b < 0) b = (-b) + n;
G[neg(a)].push_back(b);
G[neg(b)].push_back(a);
G2[b].push_back(neg(a));
G2[a].push_back(neg(b));
}
for (int i = 1; i <= 2*n; ++i)
if (!viz[i]) df(i);
memset(viz, false, sizeof(viz));
for (int i = 2*n; i; --i)
if (!viz[st[i]]) df2(st[i]);
if(no_sol) printf("-1\n");
else
for (int i = 1; i <= n; ++i)
printf("%d ", value[i]);
}