bzoj4668 冷战

一点也不优雅的LCT大力跑过去了23333.标算是并查集加特技...

#include<cstdio>
#include<algorithm>
using namespace std;
const int maxn=500005;
struct node{
  node* ch[2],*prt;
  bool mk,isroot;
  int val,Max;
  void rev(){
    swap(ch[0],ch[1]);mk^=1;
  }
  void pd(){
    if(mk){
      mk=0;
      if(ch[0])ch[0]->rev();
      if(ch[1])ch[1]->rev();
    }
  }
  void upd(){
    Max=val;
    if(ch[0])Max=max(Max,ch[0]->Max);
    if(ch[1])Max=max(Max,ch[1]->Max);
  }
}t[maxn*2];
inline int isch1(node* rt){return rt==rt->prt->ch[1];}
void rot(node* rt,int t){
  node* p=rt->prt,*c=rt->ch[t];
  c->pd();
  if(rt->isroot)rt->isroot=false,c->isroot=true;
  else p->ch[isch1(rt)]=c;
  c->prt=p;
  rt->ch[t]=c->ch[t^1];if(c->ch[t^1])c->ch[t^1]->prt=rt;
  c->ch[t^1]=rt;rt->prt=c;
  rt->upd();c->upd();
}
void splay(node* rt){
  node* p,* g;
  while(!rt->isroot){
    p=rt->prt;
    if(p->isroot){
      p->pd();
      rot(p,isch1(rt));
    }else{
      g=p->prt;g->pd();p->pd();
      int t1=isch1(rt),t2=isch1(p);
      if(t1==t2){
	rot(g,t2);rot(p,t1);
      }else{
	rot(p,t1);rot(g,t2);
      }
    }
  }
  rt->pd();
}
void access(node* rt){
  node* last=0;
  while(rt){
    splay(rt);
    if(rt->ch[1]){
      rt->ch[1]->isroot=true;
    }
    rt->ch[1]=last;
    if(last)last->prt=rt,last->isroot=false;
    rt->upd();
    last=rt;rt=rt->prt;
  }
}
int findroot(int x){
  node* p=t+x;
  access(p);splay(p);
  while(p->ch[0])p=p->ch[0];
  return p-t;
}
void makeroot(int x){
  access(t+x);splay(t+x);t[x].rev();
}
void link(int u,int v){
  makeroot(u);t[u].prt=(t+v);
}
int lastans=0;
int main(){
  int n,m;scanf("%d%d",&n,&m);
  for(int i=1;i<=n;++i)t[i].isroot=true,t[i].val=t[i].Max=0;
  int typ,u,v;
  int cntedge=0;
  while(m--){
    scanf("%d%d%d",&typ,&u,&v);
    u^=lastans;v^=lastans;
    if(typ==0){
      ++cntedge;
      if(findroot(u)!=findroot(v)){
	t[n+cntedge].isroot=true;t[n+cntedge].Max=t[n+cntedge].val=cntedge;
	link(u,n+cntedge);link(n+cntedge,v);
      }
    }else{
      if(findroot(u)!=findroot(v))printf("%d
",lastans=0);
      else{
	makeroot(u);access(t+v);splay(t+v);
	printf("%d
",lastans=t[v].Max);
      }
    }

  }
  return 0;
}