做了几道LCT的题后发现终于会打裸题啦QAQ
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<queue>
#include<set>
#include<map>
#include<vector>
#include<algorithm>
#include<iostream>
#define N 303333
using namespace std;
int sc()
{
int i=0,f=1; char c=getchar();
while(c>'9'||c<'0'){if(c=='-')f=-1; c=getchar();}
while(c>='0'&&c<='9') i=i*10+c-'0',c=getchar();
return i*f;
}
bool rev[N];
int v[N],val[N],fa[N],ch[N][2],st[N];
int n,m;
bool Root(int x){return ch[fa[x]][0]!=x&&ch[fa[x]][1]!=x;}
void push_up(int x)
{
val[x]=val[ch[x][0]]+val[ch[x][1]]+v[x];
}
void push_down(int x)
{
if(rev[x])
{
rev[ch[x][0]]^=1;rev[ch[x][1]]^=1;
swap(ch[x][1],ch[x][0]);rev[x]=0;
}
}
void rotate(int x)
{
int y=fa[x],z=fa[y],l,r;
l=(ch[y][1]==x);r=l^1;
if(!Root(y))ch[z][ch[z][1]==y]=x;
fa[x]=z;fa[y]=x;fa[ch[x][r]]=y;
ch[y][l]=ch[x][r];ch[x][r]=y;
push_up(y),push_up(x);
}
void splay(int x)
{
int top=1;st[1]=x;
for(int i=x;!Root(i);i=fa[i])st[++top]=fa[i];
while(top)push_down(st[top--]);
while(!Root(x))
{
int y=fa[x],z=fa[y];
if(!Root(y))
if(ch[z][0]==y^ch[y][0]==x)rotate(x);
else rotate(y);
rotate(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 make_root(int x)
{
access(x),splay(x),rev[x]^=1;
}
void link(int x,int y)
{
make_root(x),fa[x]=y;
}
void cut(int x,int y)
{
make_root(x),access(y),splay(y);
fa[x]=ch[y][0]=0,push_up(y);
}
int find(int x)
{
access(x),splay(x);
while(ch[x][0])x=ch[x][0],push_down(x);
return x;
}
int main()
{
n=sc();
for(int i=1;i<=n;i++)v[i]=val[i]=sc();
m=sc();
while(m--)
{
char s[11]; scanf("%s",s);
if(s[0]=='b')
{
int x=sc(),y=sc();
if(find(x)!=find(y))
{
puts("yes");
link(x,y);
}
else puts("no");
}
else if(s[0]=='p')
{
int x=sc(),y=sc();
make_root(x),v[x]=y;
push_up(x);
}
else if(s[0]=='e')
{
int x=sc(),y=sc();
int fx=find(x),fy=find(y);
if(fx==fy)
{
make_root(x);
access(y);
splay(y);
printf("%d\n",val[y]);
}
else puts("impossible");
}
}
return 0;
}