Cod sursa(job #1135604)

Utilizator Al3ks1002Alex Cociorva Al3ks1002 Data 8 martie 2014 02:26:45
Problema 2SAT Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.17 kb
#include<cstdio>
#include<vector>
#include<bitset>
#include<cstring>

using namespace std;
const int nmax = 100005;
int n,m,i,x,y,tsort[2*nmax],cnt,comp[2*nmax];
vector<int> v[2*nmax];
vector<int> vt[2*nmax];
bool viz[2*nmax];

#define v (v+nmax)
#define vt (vt+nmax)
#define comp (comp+nmax)
#define viz (viz+nmax)

void dfs(int x)
{
    viz[x]=1;
    for(vector<int>::iterator it=v[x].begin();it!=v[x].end();it++)
        if(!viz[*it]) dfs(*it);
    tsort[++cnt]=x;
}

void dfst(int x)
{
    viz[x]=1; comp[x]=cnt;
    for(vector<int>::iterator it=vt[x].begin();it!=vt[x].end();it++)
        if(!viz[*it]) dfst(*it);
}

int main()
{
	freopen("2sat.in","r",stdin);
	freopen("2sat.out","w",stdout);

	scanf("%d%d",&n,&m);
	for(;m;m--)
	{
	    scanf("%d%d",&x,&y);
	    v[-x].push_back(y);
	    v[-y].push_back(x);
	    vt[y].push_back(-x);
	    vt[x].push_back(-y);
	}

	for(i=-n;i<=n;i++) if(!viz[i] && i) dfs(i);
	for(i=-n;i<=n;i++) viz[i]=0; cnt=0;
	for(i=2*n;i;i--) if(!viz[tsort[i]]) {cnt++; dfst(tsort[i]);}

    for(i=1;i<=n;i++) if(comp[i]==comp[-i]) {printf("-1\n"); return 0;}
    for(i=1;i<=n;i++) printf("%d ",comp[i]>comp[-i]);

	return 0;
}