F. Radio Stations

Portal

Topic look half: "woc bare $ 2-sat $ white to ??"

After reading: "... ???"

 

If there is no restriction $ f $, that is a white to a $ 2-sat $ problem, but now there is this limit ...

Direct enumeration of $ f $ Obviously not, considering the $ f $ also included $ 2-sat $ model we built

For a limited $ [l, r] $ station, if we select it, then all $ r '$ $ L is smaller than the station and $ $ l' $ R & lt station is greater than $ $ are not selected

So a form of violence is twenty-two enumeration to see if the conflict is clearly still $ T $ Fly

Taking into account a $ ri> rj $, $ RI $ and station conflicts must likewise RJ $ and $ conflict, consider building dummy node chain $ np [] $, $ np [i] $ connected to $ np [i + 1] $

For $ ri $, corresponding to the nodes of the virtual link $ np [ri] $, then for each point of $ X $ $ rx $, $ X $ side even to $ np [rx + 1] $, for each point X $ $ $ a $ LX connected side $ np [lx] $ to $ m + x $

(Where $ m $ and $ m $ subject is not the same, obviously represents $ m + x $ $ X $ is not selected, $ X $ $ X $ represents optional)

After this composition, if $ X $ is selected, then all greater than $ $ $ Li RX node $ $ I $, will be connected to $ m + i $ (i.e., not selected)

For $ l $ limit is almost the same structure, they painted a picture of it

Specific reference code implementation  DTSBT  , when the code that implements the operation is relatively Sao depends know how to think about it (for me ...)

The array size to a little note, do not like me indiscriminate

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<vector>
using namespace std;
typedef long long ll;
inline int read()
{
    int x=0,f=1; char ch=getchar();
    while(ch<'0'||ch>'9') { if(ch=='-') f=-1; ch=getchar(); }
    while(ch>='0'&&ch<='9') { x=(x<<1)+(x<<3)+(ch^48); ch=getchar(); }
    return x*f;
}
const int N=2e6+7;
int n,m,p,q,L[N],R[N];
vector <int> Tl[N],Tr[N];
int fir[N],from[N<<1],to[N<<1],cntt;
inline void add(int a,int b) { from[++cntt]=fir[a]; fir[a]=cntt; to[cntt]=b; }
int dfn[N],low[N],dfs_clock,bel[N],tot,st[N],Top;
void Tarjan(int x)
{
    dfn[x]=low[x]=++dfs_clock; st[++Top]=x;
    for(int i=fir[x];i;i=from[i])
    {
        int &v=to[i];
        if(!dfn[v]) Tarjan(v),low[x]=min(low[x],low[v]);
        else if(!bel[v]) low[x]=min(low[x],dfn[v]);
    }
    if(low[x]==dfn[x])
    {
        tot++;
        while(st[Top]!=x) bel[st[Top--]]=tot;
        bel[st[Top--]]=tot;
    }
}
int main()
{
    n=read(),m=read(),p=read(),q=read(); int a,b;
    for(int i=1;i<=n;i++)
    {
        a=read(),b=read();
        add(m+a,b); add(m+b,a);
    }
    for(int i=1;i<=m;i++)
    {
        L[i]=read(),R[i]=read();
        Tl[L[i]].push_back(i); Tr[R[i]].push_back(i);
    }
    for(int i=1;i<=q;i++)
    {
        a=read(),b=read();
        add(a,m+b); add(b,m+a);
    }
    int cnt=m*2,ta=++cnt,tb=++cnt;
    for(int i=1;i<=p;i++)
    {
        for(auto x: Tl[i]) add(x,ta),add(tb,m+x);
        for(auto x: Tr[i])
        {
            cnt++; add(cnt,ta); add(cnt,m+x); ta=cnt;
            cnt++; add(tb,cnt); add(x,cnt); tb=cnt;
        }
    }
    for(int i=1;i<=2*m;i++) if(!dfn[i]) Tarjan(i);
    for(int i=1;i<=m;i++) if(bel[i]==bel[m+i]) { printf("-1\n"); return 0; }
    int ans=0; vector <int> V;
    for(int i=1;i<=m;i++)
        if(bel[i]<bel[i+m]) ans=max(ans,L[i]),V.push_back(i);
    printf("%d %d\n",int(V.size()),ans);
    for(auto x: V) printf("%d ",x); printf("\n");
    return 0;
}