BZOJ 4668 LCT

//By SiriusRen
#include <bits/stdc++.h>
using namespace std;
const int N=1000050;
int n,m,op,xx,yy,top,lastans,T;
int fa[N],ch[N][2],q[N],maxx[N],rev[N],v[N],f[N];
bool isroot(int x){return ch[fa[x]][0]!=x&&ch[fa[x]][1]!=x;}
void push_up(int x){maxx[x]=max(v[x],max(maxx[ch[x][0]],maxx[ch[x][1]]));}
void push_down(int x){if(rev[x])rev[ch[x][0]]^=1,rev[ch[x][1]]^=1,rev[x]=0,swap(ch[x][0],ch[x][1]);}
void rotate(int p){
    int q=fa[p],y=fa[q],x=(ch[q][1]==p);
    ch[q][x]=ch[p][!x],fa[ch[q][x]]=q;
    ch[p][!x]=q,fa[p]=y;
    if(!isroot(q)){
        if(ch[y][0]==q)ch[y][0]=p;
        if(ch[y][1]==q)ch[y][1]=p;
    }fa[q]=p,push_up(q);
}
void splay(int x){
    q[++top]=x;
    for(int i=x;!isroot(i);i=fa[i])q[++top]=fa[i];
    while(top)push_down(q[top]),top--;
    for(int y=fa[x];!isroot(x);rotate(x),y=fa[x])if(!isroot(y)){
        if((ch[y][0]==x)^(ch[fa[y]][0]==y))rotate(x);
        else rotate(y);
    }push_up(x);
}
void access(int x){for(int t=0;x;t=x,x=fa[x])splay(x),ch[x][1]=t,push_up(x);}
void makeroot(int x){access(x),splay(x),rev[x]^=1;}
void link(int x,int y){makeroot(x),fa[x]=y;}
void split(int x,int y){makeroot(x),access(y),splay(y);}
int find(int x){return x==f[x]?x:f[x]=find(f[x]);}
int main(){
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)f[i]=i;
    for(int i=1;i<=m;i++){
        scanf("%d%d%d",&op,&xx,&yy);
        xx^=lastans,yy^=lastans;
        if(op){
            int fx=find(xx),fy=find(yy);
            if(fx!=fy)printf("%d\n",lastans=0);
            else split(xx,yy),printf("%d\n",lastans=maxx[yy]);
        }
        else{
            T++;
            int fx=find(xx),fy=find(yy);
            if(fx!=fy){
                f[fx]=fy,v[n+T]=maxx[n+T]=T;
                link(xx,n+T),link(n+T,yy);
            }
        }
    }
}