Cod sursa(job #2338488)

Utilizator refugiatBoni Daniel Stefan refugiat Data 7 februarie 2019 15:48:27
Problema 2SAT Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.53 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <bitset>
#include <stack>
#define NMAX 200005
using namespace std;
ifstream si("2sat.in");
ofstream so("2sat.out");
vector<int>g[NMAX];
vector<int>gt[NMAX];
bitset<NMAX>vaz;
bitset<NMAX>sol;
stack<int> ord;
int n;
bool ok=true;
int neg(int a) {
    if(a>n)
        a-=n;
    else
        a+=n;
    return a;
}
void adaug(int a,int b) {
    g[a].push_back(b);
    gt[b].push_back(a);
}
void dfs1(int nod) {
    vaz[nod]=1;
    int l=g[nod].size();
    for(int i=0; i<l; ++i)
    {
        if(!vaz[g[nod][i]])
            dfs1(g[nod][i]);
    }
    ord.push(nod);
}
void dfs2(int nod) {
    if(sol[nod]) {
        ok=false;
        return;
    }
    vaz[nod]=sol[nod]=0;
    sol[neg(nod)]=1;
    int l=gt[nod].size();
    for(int i=0; i<l; ++i) {
        if(vaz[gt[nod][i]]) {
            dfs2(gt[nod][i]);
        }
    }
}
int main() {
    int m;
    si>>n>>m;
    int a,b;
    for(int i=0; i<m; ++i) {
        si>>a>>b;
        if(a<0)
            a=n-a;
        if(b<0)
            b=n-b;
        adaug(neg(a),b);
        adaug(neg(b),a);
    }
    for(int i=1; i<=n+n; ++i) {
        if(!vaz[i]) {
            dfs1(i);
        }
    }
    while(!ord.empty()) {
        a=ord.top();
        ord.pop();
        if(vaz[a]&&vaz[neg(a)])
            dfs2(a);
    }
    if(!ok)
        so<<"-1\n";
    else
    {
        for(int i=1; i<=n; ++i)
            so<<sol[i]<<' ';
        so<<'\n';
    }
    return 0;
}