完整版2-sat模板

rt

#include<iostream>
#include<cstring>
#include<algorithm>
#include<cstdio>
#include<vector>
#include<sstream>
#include<string>
#include<climits>
#include<stack>
#include<set>
#include<bitset>
#include<cmath>
#include<deque>
#include<map>
#include<queue>
#define iinf 2000000000
#define linf 1000000000000000000LL
#define dinf 1e200
#define eps 1e-11
#define all(v) (v).begin(),(v).end()
#define sz(x)  x.size()
#define pb push_back
#define mp make_pair
#define lng long long
#define sqr(a) ((a)*(a))
#define pii pair<int,int>
#define pll pair<lng,lng>
#define pss pair<string,string>
#define pdd pair<double,double>
#define X first
#define Y second
#define pi 3.14159265359
#define ff(i,xi,n) for(int i=xi;i<=(int)(n);++i)
#define ffd(i,xi,n) for(int i=xi;i>=(int)(n);--i)
#define ffl(i,r) for(int i=head[r];i!=-1;i=edge[i].next)
#define cc(i,j) memset(i,j,sizeof(i))
#define two(x)			((lng)1<<(x))
#define N 2111
#define M 1000000
#define lson l , mid , rt << 1
#define rson mid + 1 , r , rt << 1 | 1
#define Mod  n
#define Pmod(x) (x%Mod+Mod)%Mod
using namespace std;
typedef vector<int>  vi;
typedef vector<string>  vs;
typedef unsigned int uint;
typedef unsigned lng ulng;
template<class T> inline void checkmax(T &x,T y){if(x<y) x=y;}
template<class T> inline void checkmin(T &x,T y){if(x>y) x=y;}
template<class T> inline T Min(T x,T y){return (x>y?y:x);}
template<class T> inline T Max(T x,T y){return (x<y?y:x);}
template<class T> T gcd(T a,T  b){return (a%b)==0?b:gcd(b,a%b);}
template<class T> T lcm(T a,T b){return a*b/gcd(a,b);}
template<class T> T Abs(T a){return a>0?a:(-a);}
template<class T> inline T lowbit(T n){return (n^(n-1))&n;}
template<class T> inline int countbit(T n){return (n==0)?0:(1+countbit(n&(n-1)));}
template<class T> inline bool isPrimeNumber(T n)
{if(n<=1)return false;for (T i=2;i*i<=n;i++) if (n%i==0) return false;return true;}
template<class T> inline T Minmin(T a,T b,T c,T d){return Min(Min(a,b),Min(c,d));}
struct ps
{
    int l,r;
}so[N*2];
bool cross(int  p,int  q)
{
    return  (so[p].l<=so[q].l)?so[p].r>so[q].l:so[q].r>so[p].l;
}
struct tarjan_seg
{
    int head[N],tot,id[N],pre[N],low[N],stack[N],top,n,Index,nn,newid,newhead[N],*cur,contain[N];
    struct pp
   {
        int v,next;
    }edge[N*2000];
    void add(int u,int v)
    {
        edge[tot].v=v;
        edge[tot].next=cur[u];
        cur[u]=tot++;
    }
    void init()
    {
        cc(head,-1);
        cc(newhead,-1);
        tot=0;
        newid=0;
        cur=head;
        cc(pre,-1);
        cc(low,-1);
        top=0;
        cc(id,-1);
        Index=0;
    }
    void tarjan(int r,int p)
    {
        bool xx=false;
        pre[r]=low[r]=++Index;
        stack[++top]=r;
        ffl(i,r)
        {
            int v=edge[i].v;
            if(v==p&&xx==0)
            {
                xx=1;
                continue;
            }
            if(pre[v]==-1)
            {
                tarjan(v,r);
                checkmin(low[r],low[v]);
            }
            else
            if(id[v]==-1)
            checkmin(low[r],pre[v]);
        }
        if(pre[r]==low[r])
        {
            int v;
            ++newid;
            do
            {
                v=stack[top--];
                id[v]=newid;
            }while(v!=r);
        }
    }
    void solve()
    {
        ff(i,1,n)
        if(pre[i]==-1)
        tarjan(i,-1);
    }
    void build_map()
    {
        int  hash[N]={};
        cur=newhead;
        ff(i,1,n)
        {
            ffl(j,i)
            {
                int v=edge[j].v;
                if(id[i]!=id[v]&&hash[id[i]]!=id[v])
                add(id[v],id[i]),hash[id[i]]=id[v];
            }
        }
    }
    void solve_contain()
    {
        cc(contain,-1);
        cur=contain;
        ff(i,1,n)
        add(id[i],i);
    }
    bool two_sat()
    {
        for(int i=1;i<=n;i+=2)
        if(id[i]==id[i+1])
        return false;
        return true;
    }
    void dfs(int r)
    {
        pre[r]=++Index;
        for(int i=newhead[r];i!=-1;i=edge[i].next)
         if(pre[edge[i].v]==-1) dfs(edge[i].v);
        low[++newid]=r;
    }
    void color_dfs(int r)
    {
        pre[r]=2;
        for(int i=newhead[r];i!=-1;i=edge[i].next)
        if(pre[edge[i].v]==-1) color_dfs(edge[i].v);
    }
    void Color()
    {
        cc(pre,-1);
       for(int i=nn;i>0;--i)
       if(pre[low[i]]==-1)
       {
          int a=edge[contain[low[i]]].v;
          int b;
          b=((a+1)/2)*4-1-a;
           pre[low[i]]=1;
           if(pre[id[b]]==-1)
           color_dfs(id[b]);
       }
    }
    void topo_sort()
    {
        nn=newid;
        Index=0;
        newid=0;
        cc(pre,-1);
        cc(low,-1);
        ff(i,1,nn)
        if(pre[i]==-1)
        dfs(i);
    }
    void taganswer()
    {
        cc(low,-1);
        ff(i,1,nn)
       if(pre[i]==1) {
         for(int j=contain[i];j!=-1;j=edge[j].next)
            low[edge[j].v]=1;
        }
    }
    void print_answer()
    {
        if(!two_sat())
        {printf("NO\n");
        return ;
        }
        printf("YES\n");
        solve_contain();
        build_map();
        topo_sort();
       Color();
       taganswer();
        ff(i,1,n)
        {
            if(low[i]==1)
            {
                printf("%d ",i);
            }
        }
    }
};