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:heavy_check_mark: verify/yosupo/graph/twosat/two_sat.test.cpp

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Code

#define PROBLEM "https://judge.yosupo.jp/problem/two_sat"
#include "template.hpp"
#include "graph/twosat.hpp"

int main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    string s;
    int n,m;
    cin >> s >> s >> n >> m;
    TwoSAT sat(n);
    for(int i=0;i<m;i++){
        int a,b,x;
        cin >> a >> b >> x;
        sat.add_clause(abs(a)-1,a<0,abs(b)-1,b<0);
    }
    auto [ok,ans]=sat.solve();
    if(ok){
        cout << "s SATISFIABLE\n";
        cout << "v ";
        for(int i=0;i<n;i++)cout << (ans[i]?i+1:-(i+1)) << " ";
        cout << "0\n";

    }else{
        cout << "s UNSATISFIABLE\n";
    }
}
#line 1 "verify/yosupo/graph/twosat/two_sat.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/two_sat"
#line 2 "template.hpp"
#include<bits/stdc++.h>

using namespace std;

using ll = long long;
using db = long double;
using i128 = __int128_t;
using u32 = uint32_t;
using u64 = uint64_t;
template<class T>
using PQ = priority_queue<T,vector<T>,greater<T>>;

const int INF=INT_MAX/2;
const ll LINF=LLONG_MAX/4;
const db DINF=numeric_limits<db>::infinity();
const db EPS=1e-9;
const db PI=acos(db(-1));

#define ALL(a) a.begin(),a.end()
#define RALL(a) a.rbegin(),a.rend()
#define SZ(a) (int)(a.size())
#define SORT(a) sort(ALL(a))
#define RSORT(a) sort(RALL(a))
#define REV(a) reverse(ALL(a))
#define UNI(a) a.erase(unique(ALL(a)),a.end())
#define LB(a,x) (int)(lower_bound(ALL(a),x)-a.begin())
#define UB(a,x) (int)(upper_bound(ALL(a),x)-a.begin())
#define FIND(a,x) (int)(find(ALL(a),x)-a.begin())
#define COUNT(a,x) (int)count(ALL(a),x)
#define MIN(a) *min_element(ALL(a))
#define MAX(a) *max_element(ALL(a))

template<class T,class U>
bool chmin(T &a,U b){return b<a?a=b,1:0;}
template<class T,class U>
bool chmax(T &a,U b){return a<b?a=b,1:0;}

template<class T>
T floor(T a,T b){return a/b-((a^b)<0&&a%b);}
template<class T>
T ceil(T a,T b){return a/b+((a^b)>=0&&a%b);}

int popcnt(ll x){return __builtin_popcountll(x);}
int topbit(ll x){return x==0?-1:63-__builtin_clzll(x);}
int lowbit(ll x){return x==0?-1:__builtin_ctzll(x);}

template<class T,class U>
T SUM(const U &a){return accumulate(ALL(a),T{});}
template<class T>
vector<int> argsort(const vector<T> &a){
    vector<int> p(SZ(a));
    iota(ALL(p),0);
    stable_sort(ALL(p),[&](int i,int j){return a[i]<a[j];});
    return p;
}

template<class T,size_t D=0>
struct VecBuilder{
    array<size_t,D> d;
    VecBuilder<T,D+1> operator[](size_t n)const{
        VecBuilder<T,D+1> res{};
        for(size_t i=0;i<D;i++)res.d[i]=d[i];
        res.d[D]=n;
        return res;
    }
    template<size_t I=0>
    auto build(const T &x)const{
        if constexpr(I+1==D)return vector<T>(d[I],x);
        else return vector<decltype(build<I+1>(x))>(d[I],build<I+1>(x));
    }
    auto operator()(const T &x=T())const{
        static_assert(D>0);
        return build(x);
    }
};
template<class T>
inline constexpr VecBuilder<T> VEC{};

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());
#line 3 "graph/twosat.hpp"

/**
 * Author: Teetat T.
 * Date: 2025-02-20
 * Description: Cartesian Tree.
 */

struct TwoSAT{
    int n;
    vector<vector<int>> adj,rev;
    TwoSAT(int _n):n(_n),adj(n*2),rev(n*2){}
    void add_edge(int u,int v){
        adj[u].emplace_back(v);
        rev[v].emplace_back(u);
    }
    void add_clause(int u,bool nu,int v,bool nv){
        u=(u<<1)|nu,v=(v<<1)|nv;
        add_edge(u^1,v);
        add_edge(v^1,u);
    }
    pair<bool,vector<bool>> solve(){
        vector<bool> vis(n*2),ans(n);
        vector<int> ord,scc(n*2);
        int scc_id=0;
        function<void(int)> dfs=[&](int u){
            if(vis[u])return;
            vis[u]=true;
            for(auto v:adj[u])dfs(v);
            ord.emplace_back(u);
        };
        function<void(int)> dfs2=[&](int u){
            if(scc[u])return;
            scc[u]=scc_id;
            for(auto v:rev[u])dfs2(v);
        };
        for(int i=0;i<2*n;i++)dfs(i);
        reverse(ord.begin(),ord.end());
        for(int i:ord)if(!scc[i]){
            scc_id++;
            dfs2(i);
        }
        for(int i=0;i<n;i++){
            if(scc[i<<1]==scc[(i<<1)|1])return {false,ans};
            ans[i]=scc[i<<1]>scc[(i<<1)|1];
        }
        return {true,ans};
    }
};
#line 4 "verify/yosupo/graph/twosat/two_sat.test.cpp"

int main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    string s;
    int n,m;
    cin >> s >> s >> n >> m;
    TwoSAT sat(n);
    for(int i=0;i<m;i++){
        int a,b,x;
        cin >> a >> b >> x;
        sat.add_clause(abs(a)-1,a<0,abs(b)-1,b<0);
    }
    auto [ok,ans]=sat.solve();
    if(ok){
        cout << "s SATISFIABLE\n";
        cout << "v ";
        for(int i=0;i<n;i++)cout << (ans[i]?i+1:-(i+1)) << " ";
        cout << "0\n";

    }else{
        cout << "s UNSATISFIABLE\n";
    }
}
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