Pagini recente » Cod sursa (job #2712507) | Cod sursa (job #1831793) | Cod sursa (job #690203) | Cod sursa (job #95308) | Cod sursa (job #3213205)
#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O2,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pi;
#define pb push_back
#define mp make_pair
#define f first
#define s second
vector<vi> adj(200005), adj_inv(200005);
vector<bool> visited(200005);
vi topological, comp(200005);
void dfs(int x){
visited[x] = 1;
for(auto i : adj[x])
if(!visited[i])
dfs(i);
topological.pb(x);
}
void dfs2(int x, int num){
visited[x] = 1;
comp[x] = num;
for(auto i : adj_inv[x])
if(!visited[i])
dfs2(i, num);
}
void solve(){
int n, m;
cin >> n >> m;
for(int i = 0; i < m; i++){
int a, b, neg_a, neg_b;
cin >> a >> b;
int na = (a < 0), nb = (b < 0);
a = abs(a) - 1, b = abs(b) - 1;
//a is 2n, neg_a is 2n+1
a = 2 * a ^ na, b = 2 * b ^ nb;
neg_a = a ^ 1, neg_b = b ^ 1;
adj[neg_a].pb(b); adj[neg_b].pb(a);
adj_inv[b].pb(neg_a); adj_inv[a].pb(neg_b);
}
for(int i = 0; i < 2*n; i++){
if(!visited[i])
dfs(i);
}
reverse(topological.begin(), topological.end());
int cnt = 0;
visited = vector<bool>(200005);
for(auto x : topological){
if(!visited[x]){
dfs2(x, cnt);
cnt++;
}
}
//i+1 is the negation, i is not
vi ans(n);
for(int i = 0; i < 2*n; i += 2){
if(comp[i] == comp[i+1]){
cout << -1 << '\n';
return;
}
if(comp[i] < comp[i+1])
ans[i/2] = 0;
else
ans[i/2] = 1;
}
for(auto i : ans)
cout << i << ' ';
cout << '\n';
}
int main(){
freopen("2sat.in", "r", stdin);
freopen("2sat.out", "w", stdout);
ios::sync_with_stdio(0); cin.tie(0);
int t = 1;
//cin >> t;
while(t--){
solve();
}
}