BZOJ 4285 使者

我TM再也不写BIT套主席树了。。。。

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define maxv 200500
#define maxe 200500
using namespace std;
int n,m,q,type,x,y,g[maxv],nume=0,dfn[maxv],mx[maxv],fdfn[maxv],dis[maxv],anc[maxv][23],times=0;
int root[maxv*2],sum[maxv*180],tot=0,ls[maxv*180],rs[maxv*180];
struct edge
{
    int v,nxt;
}e[maxe];
void addedge(int u,int v)
{
    e[++nume].v=v;
    e[nume].nxt=g[u];
    g[u]=nume;
}
int lowbit(int x)
{
    return (x&(-x));
}
void dfs(int x,int fath)
{
    dfn[x]=++times;fdfn[times]=x;mx[x]=dfn[x];
    for (int i=g[x];i;i=e[i].nxt)
    {
        int v=e[i].v;
        if (v!=fath)
        {
            anc[v][0]=x;dis[v]=dis[x]+1;
            dfs(v,x);
            mx[x]=max(mx[x],mx[v]);
        }
    }
}
void build(int &now,int left,int right)
{
    now=++tot;sum[now]=0;
    if (left==right) return;
    int mid=(left+right)>>1;
    build(ls[now],left,mid);
    build(rs[now],mid+1,right);
}
void get_table()
{
    for (int e=1;e<=20;e++)
        for (int i=1;i<=n;i++)
            anc[i][e]=anc[anc[i][e-1]][e-1];
}
int lca(int x,int y)
{
    if (dis[x]<dis[y]) swap(x,y);
    if (dis[x]!=dis[y])
    {
        for (int e=20;e>=0;e--)
        {
            if ((dis[anc[x][e]]>=dis[y]) && (anc[x][e]))
                x=anc[x][e];
        }
    }
    if (x==y) return x;
    for (int e=20;e>=0;e--)
    {
        if (anc[x][e]!=anc[y][e])
        {
            x=anc[x][e];
            y=anc[y][e];
        }
    }
    return anc[x][0];
}
int find(int x,int pos)
{
    for (int e=20;e>=0;e--)
        if (dis[anc[x][e]]>dis[pos])
            x=anc[x][e];
    return x;
}
void modify(int last,int x,int pos,int val)
{
    root[x]=++tot;
    int now=root[x];sum[now]=sum[last]+val;
    int left=1,right=n;
    while (left<right)
    {
        int mid=(left+right)>>1;
        ls[now]=ls[last];rs[now]=rs[last];
        if (pos<=mid)
        {
            ls[now]=++tot;
            sum[ls[now]]=sum[ls[last]]+val;
            now=ls[now];last=ls[last];right=mid;
        }
        else
        {
            rs[now]=++tot;
            sum[rs[now]]=sum[rs[last]]+val;
            now=rs[now];last=rs[last];left=mid+1;
        }
    }
}
void add(int x,int pos,int val)
{
    for (int i=x;i<=n;i+=lowbit(i))
        modify(root[i],i,pos,val);
}
void build_tree()
{
    build(root[0],1,n);
    for (int i=1;i<=n;i++)
    {
        root[i]=++tot;
        ls[root[i]]=ls[root[i-1]];rs[root[i]]=rs[root[i-1]];
    }
    scanf("%d",&m);
    for (int i=1;i<=m;i++)
    {
        scanf("%d%d",&x,&y);
        add(dfn[x],dfn[y],1);
        add(dfn[y],dfn[x],1);
    }
}
int ask(int now,int left,int right,int l,int r)
{
    if ((left==l) && (right==r))
        return sum[now];
    int mid=(left+right)>>1;
    if (r<=mid) return ask(ls[now],left,mid,l,r);
    else if (l>=mid+1) return ask(rs[now],mid+1,right,l,r);
    else return ask(ls[now],left,mid,l,mid)+ask(rs[now],mid+1,right,mid+1,r);
}
int ask_(int now,int left,int right)
{
    int ret=0;
    for (int i=now;i>=1;i-=lowbit(i))
        ret+=ask(root[i],1,n,left,right);
    return ret;
}
int main()
{
    scanf("%d",&n);
    for (int i=1;i<=n-1;i++)
    {
        scanf("%d%d",&x,&y);
        addedge(x,y);addedge(y,x);
    }
    dfs(1,1);
    get_table();
    build_tree();
    scanf("%d",&q);
    for (int i=1;i<=q;i++)
    {
        scanf("%d%d%d",&type,&x,&y);
        if (type==1)
        {
            add(dfn[x],dfn[y],1);
            add(dfn[y],dfn[x],1);
        }
        else if (type==2)
        {
            add(dfn[x],dfn[y],-1);
            add(dfn[y],dfn[x],-1);
        }
        else
        {
            int t=lca(x,y);
            if (t==y)
            {
                int r=find(x,y);
                int ret1=ask_(mx[x],1,n)-ask_(dfn[x]-1,1,n);
                int ret2=ask_(mx[x],dfn[r],mx[r])-ask_(dfn[x]-1,dfn[r],mx[r]);
                printf("%d\n",ret1-ret2);
            }
            else if (t==x)
            {
                int r=find(y,x);
                int ret1=ask_(n,dfn[y],mx[y]);
                int ret2=ask_(mx[r],dfn[y],mx[y])-ask_(dfn[r]-1,dfn[y],mx[y]);
                printf("%d\n",ret1-ret2);
            }
            else
                printf("%d\n",ask_(mx[x],dfn[y],mx[y])-ask_(dfn[x]-1,dfn[y],mx[y]));
        }
    }
    return 0;
}