1 #include<bits/stdc++.h>
2 using namespace std;
3 int fa[500010],ch[500010][2],sum[500010],v[500010],rev[500010],lb[500010],bf[500010][3],n,q,type,ty,last;
4 bool root(int x){ return ((fa[x]==0)or((ch[fa[x]][0]!=x)and(ch[fa[x]][1]!=x))); }
5 bool lch(int x){ return (ch[fa[x]][0]==x); }
6 void up(int x){ sum[x]=sum[ch[x][0]]+v[x]+sum[ch[x][1]]; }
7 void down(int x)
8 {
9 if(rev[x]==0)return;
10 rev[x]=0; swap(ch[x][0],ch[x][1]); if(ch[x][0])rev[ch[x][0]]^=1; if(ch[x][1])rev[ch[x][1]]^=1;
11 }
12 void rot(int x)
13 {
14 if((x==0)or(root(x)))return;
15 int y=fa[x]; int t=fa[y];
16 if(ch[t][0]==y)ch[t][0]=x;else if(ch[t][1]==y)ch[t][1]=x; fa[x]=t; fa[y]=x;
17 if(ch[y][0]==x){ ch[y][0]=ch[x][1]; if(ch[x][1])fa[ch[x][1]]=y; ch[x][1]=y; }
18 else{ ch[y][1]=ch[x][0]; if(ch[x][0])fa[ch[x][0]]=y; ch[x][0]=y; }
19 up(y); up(x); if(t)up(t);
20 }
21 void splay(int x)
22 {
23 if(x==0)return; int xx=x; int cnt=0;
24 while(!root(xx)){ lb[++cnt]=xx; xx=fa[xx]; } lb[++cnt]=xx;
25 for(int i=cnt;i>=1;i--)down(lb[i]);
26 while(!root(x)){ if(!root(fa[x])){ if((lch(x))^(lch(fa[x])))rot(x);else rot(fa[x]); } rot(x); }
27 }
28 int access(int x)
29 {
30 int t=0;
31 while(x!=0){ splay(x); ch[x][1]=t; up(x); if(t)fa[t]=x; t=x; x=fa[x]; }
32 return t;
33 }
34 void cut(int x,int y)
35 {
36 access(x); int z=access(y); splay(x);
37 if(x==z){ ch[x][1]=0; fa[y]=0; up(x); }else fa[x]=0;
38 }
39 void link(int x,int y)
40 {
41 access(x); splay(x); rev[x]^=1; fa[x]=y;
42 }
43 int qsum(int x,int y)
44 {
45 access(x); int z=access(y); splay(x);
46 if(x==z)return v[x]+sum[ch[x][1]];else return sum[x]+v[z]+sum[ch[z][1]];
47 }
