bzoj5329: [Sdoi2018]战略游戏

大家都说是裸题。。。

圆方树把图变成树，看虚树上有多少圆点即可

#include<cstdio>
#include<iostream>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<cmath>
#include<vector>
using namespace std;
const int _=1e2;
const int maxn=1e5+_;
const int maxm=2*1e5+_;
int read()
{
    int x=0,f=1;char ch=getchar();
    while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
    while(isdigit(ch)){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}
void write(int x)
{
    if(x>=10)write(x/10);
    putchar(x%10+'0');
}
struct node
{
    int x,y,next;
}a[2*2*maxm];int len,last[2*maxn];
void ins(int x,int y)
{
//    printf("%d %d
",x,y);
    len++;
    a[len].x=x;a[len].y=y;
    a[len].next=last[x];last[x]=len;
}

//-----------------------------------------def----------------------------------------------------

int vz,dfn[maxn],low[maxn];
int top,sta[2*2*maxn];
int cnt;vector<int>vec[maxn];
void V_DCC(int x)
{
    dfn[x]=low[x]=++vz;
    sta[++top]=x;
    for(int k=last[x];k;k=a[k].next)
    {
        int y=a[k].y;
        if(dfn[y]==0)
        {
            V_DCC(y);
            low[x]=min(low[x],low[y]);
            if(low[y]>=dfn[x])
            {
                cnt++;vec[cnt].clear();
                int i;
                do
                {
                    i=sta[top];top--;
                    vec[cnt].push_back(i);
                }while(i!=y);
                vec[cnt].push_back(x);
            }
        }
        else low[x]=min(low[x],dfn[y]);
    }
}
void maketree(int id)
{
    len=1;memset(last,0,sizeof(last));
    for(int i=1;i<=cnt;i++)
    {
        id++;
        for(int j=0;j<vec[i].size();j++)
            ins(id,vec[i][j]),ins(vec[i][j],id);
    }
}

//-----------------------------------------------composition------------------------------------------

int lim,num[2*maxn];
int z,ys[2*maxn];
int    fa[30][2*maxn],dep[2*maxn];
void dfs(int x)
{
    for(int i=1;(1<<i)<=dep[x];i++)fa[i][x]=fa[i-1][fa[i-1][x]];
    ys[x]=++z;
    for(int k=last[x];k;k=a[k].next)
    {
        int y=a[k].y;
        if(y!=fa[0][x])
        {
            fa[0][y]=x;
            dep[y]=dep[x]+1;
            num[y]=num[x]+(y<=lim);
            dfs(y);
        }
    }
}
int LCA(int x,int y)
{
    if(dep[x]<dep[y])swap(x,y);
    for(int i=25;i>=0;i--)
        if(dep[x]-dep[y]>=(1<<i))x=fa[i][x];
    if(x==y)return x;
    for(int i=25;i>=0;i--)
        if(dep[x]>=(1<<i)&&fa[i][x]!=fa[i][y])x=fa[i][x],y=fa[i][y];
    return fa[0][x];
}

//-----------------------------------------------prepare--------------------------------------------

int p[maxn],ans;
bool cmp(int p1,int p2){return ys[p1]<ys[p2];}
void VirtualTree(int m)
{
    sort(p+1,p+m+1,cmp);
    top=1;sta[top]=p[1];
    for(int i=2;i<=m;i++)
    {
        if(LCA(p[i],sta[top])==sta[top])
            {sta[++top]=p[i];continue;}
        
        while(top>1&&LCA(p[i],sta[top-1])!=sta[top-1])
            ans+=num[sta[top]]-num[sta[top-1]],top--;
            
        if(top==1||LCA(p[i],sta[top])!=sta[top-1])
        {
            int lca=LCA(p[i],sta[top]);
            ans+=num[sta[top]]-num[lca],top--;
            sta[++top]=lca;
            sta[++top]=p[i];
        }
        else
        {
            ans+=num[sta[top]]-num[sta[top-1]],top--;
            sta[++top]=p[i];
        }
    }
    while(top>1)
        ans+=num[sta[top]]-num[sta[top-1]],top--;
    ans+=num[sta[top]]-num[fa[0][sta[top]]];
}

int main()
{
    freopen("a.in","r",stdin);
    freopen("a.out","w",stdout);
    int T;
    T=read();
    while(T--)
    {
        int n,m,x,y;
        n=read(),m=read();
        len=1;memset(last,0,sizeof(last));
        for(int i=1;i<=m;i++)
        {
            x=read(),y=read();
            ins(x,y),ins(y,x);
        }
//        puts("");
        vz=top=cnt=0;
        memset(dfn,0,sizeof(dfn));
        V_DCC(1);
        maketree(n);
        num[1]=1;lim=n;dfs(1);
//        puts("");
        
        //....pre.....
        
        int Q;
        Q=read();
        while(Q--)
        {
            m=read();
            for(int i=1;i<=m;i++)p[i]=read();
            ans=0;
            VirtualTree(m);
            write(ans-m),putchar('
');
        }
//        break;
    }
    return 0;
}