Cod sursa(job #466547)

Utilizator wefgefAndrei Grigorean wefgef Data 27 iunie 2010 00:03:18
Problema Andrei Scor Ascuns
Compilator cpp Status done
Runda Marime 1.4 kb
#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] = true;
  value[neg(nod)] = true;
  for (vector<int>::iterator it = G2[nod].begin(); it != G2[nod].end(); ++it)
    if (!viz[*it]) df2(*it);
}

void OR(int a, int b) {
  G[neg(a)].push_back(b);
  G[neg(b)].push_back(a);
  G2[b].push_back(neg(a));
  G2[a].push_back(neg(b));
}

int main() {
  freopen("andrei.in", "r", stdin);
  freopen("andrei.out", "w", stdout);

  scanf("%d %d", &n, &m);
  for (int i = 0; i < m; ++i) {
    int a, b, c;
    scanf("%d %d %d", &a, &b, &c);
    if (c == 1) OR(neg(a), neg(b));
    else if (c == 0) OR(a, b);
    else {
        OR(a, neg(b));
        OR(neg(a), 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]] && !viz[neg(st[i])])
      df2(st[i]);

  if (no_sol) printf("-1\n");
  else
    for (int i = 1; i <= n; ++i)
      printf("%d%s", value[i], i == n ? "\n" : " ");
}