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#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
class List {
public:
List()
{
size = 0;
first = NULL;
}
void Insert(int value)
{
Nod *temp = new Nod;
temp->value = value;
temp->next = first;
first = temp;
size++;
}
int Size()
{
return size;
}
int operator[](int index)
{
if (index >= size || index < 0)
{
throw "Element not found!";
}
else
{
Nod* temp = first;
for (int i = 0; i < size - index - 1; i++)
temp = temp->next;
return temp->value;
}
}
private:
struct Nod {
int value;
Nod* next;
};
Nod* first;
int size;
};
ifstream f("2sat.in");
ofstream g("2sat.out");
int n, m, nrComponenteConexe; // n = nr variabile, m = nr clauze
List digraf[200001];
vector<int> vizitat, stiva, culoare;
void citire()
{
f >> n >> m;
for (int i = 1; i <= m; i++)
{
int x1, x2;
f >> x1 >> x2;
x1 = (x1 <= 0 ? -x1 : x1 + n);
x2 = (x2 <= 0 ? -x2 : x2 + n);
if (x1<= n)
{
if (x2 <= n) // !x1 V !x2 = x1 -> !x2 = x2 -> !x1
{
digraf[x2].Insert(n + x1);
digraf[x1].Insert(n + x2);
}
else // !x1 V x2 = !x2 -> !x1 = x1 -> x2
{
digraf[x1].Insert(x2 - n);
digraf[x2].Insert(x1 + n);
}
}
else
{
if (x2 <= n) // x1 V !x2 = !x1 -> !x2 = x2 -> x1
{
digraf[x2].Insert(x1 - n);
digraf[x1].Insert(x2 + n);
}
else // x1 V x2 = !x1 -> x2 = !x2 -> x1
{
digraf[x2].Insert(x1 - n);
digraf[x1].Insert(x2 - n);
}
}
}
}
void afisare()
{
for (int i = 1; i <= 2 * n; i++)
{
cout << i << " : ";
for (int j = 0; j < digraf[i].Size(); j++)
cout << digraf[i][j] << " ";
cout << endl;
}
cout << "-------------------------------" << endl;
}
void dfs(int nod)
{
vizitat[nod] = 1;
for (int j = 0; j < digraf[nod].Size(); j++)
if (vizitat[digraf[nod][j]] == 0)
dfs(digraf[nod][j]);
stiva.push_back(nod);
}
void dfs2(int nod, int nrCuloare)
{
culoare[nod] = nrCuloare;
for (int j = 0; j < digraf[nod].Size(); j++)
if (culoare[digraf[nod][j]] == 0)
dfs2(digraf[nod][j], nrCuloare);
}
void kosaraju()
{
for (int i = 1; i <= 2 * n + 1; i++)
{
vizitat.push_back(0);
culoare.push_back(0);
}
for (int i = 1; i <= 2 * n; i++)
if (vizitat[i] == 0)
dfs(i);
int nrCuloare = 1;
for (unsigned i = 0; i < stiva.size(); i++)
if (culoare[stiva[i]] == 0)
{
dfs2(stiva[i], nrCuloare);
nrCuloare++;
}
nrComponenteConexe = nrCuloare - 1;
}
void literaliContrari()
{
for (int lit1 = 1; lit1 < 2 * n; lit1++)
for (int lit2 = lit1+1; lit2 <= 2 * n; lit2++)
if (culoare[lit1] == culoare[lit2] && lit1 != lit2)
{
if (lit1 <= n && lit1 + n == lit2)
{
g << -1;
return;
}
else if (lit2 <= n && lit2 + n == lit1)
{
g << -1;
return;
}
}
}
void parcurgereTopologica()
{
bool *valoare = new bool[n+1];
for (int i = nrComponenteConexe; i >= 1; i--)
{
for (int j = 1; j <= 2 * n; j++)
if (culoare[j] == i)
{
if (i > nrComponenteConexe/2)
{
if (j <= n)
valoare[j] = 1;
else
valoare[j-n] = 0;
}
}
}
for (int i = 1; i <= n; i++)
g << !valoare[i] << " ";
}
int main()
{
citire();
//afisare();
kosaraju();
literaliContrari();
parcurgereTopologica();
f.close();
g.close();
}