真·LCT模板

#include<bits/stdc++.h>
#define maxx 400005
using namespace std;
int c[maxx][2],val[maxx],fa[maxx],dis[maxx];
bool rev[maxx];
struct node{
	int st[maxx];
	int tp;
	bool empty(){return tp==0;}
	void pop(){st[tp--]=0;}
	void push(int x){st[++tp]=x;}
	int top(){return st[tp];}
}s;
bool pdroot(int x){return (c[fa[x]][0]==x||c[fa[x]][1]==x);}
void put_up(int x){dis[x]=dis[c[x][0]]^dis[c[x][1]]^val[x];}
void zychange(int x)
{
	rev[x]^=1;
	swap(c[x][0],c[x][1]);
}
void put_down(int x)
{
	if(rev[x])
	{
		if(c[x][0])zychange(c[x][0]);
		if(c[x][1])zychange(c[x][1]);
		rev[x]=0;
	}
}
void rot(int x)
{
	int y=fa[x],z=fa[y];
	int l=(c[y][1]==x),r=l^1;
	if(pdroot(y))c[z][c[z][1]==y]=x;
	fa[x]=z;
	fa[y]=x;
	fa[c[x][r]]=y;
	c[y][l]=c[x][r];c[x][r]=y;//注意 这个语句顺序不能换！！（卡了我半小时……） 
	put_up(y);
    put_up(x);
}
void splay(int x)
{	
	int y=x;
	s.push(y);
	while(pdroot(y))
	{
		y=fa[y];
		s.push(y);
	}
	while(!s.empty())
	{
		put_down(s.top());
		s.pop();
	}
	while(pdroot(x))
	{
		int y=fa[x],z=fa[y];
		int l=(c[y][1]==x),l1=(c[z][1]==y);
		if(pdroot(y))
		{
			if(l^l1)rot(x);
			else rot(y);
		}
		rot(x);
	}
	put_up(x);
}
void access(int x)
{
	for(int y=0;x;x=fa[y=x])
	{
		splay(x);
		c[x][1]=y;
		put_up(x);
	}
}
void makeroot(int x)
{
	access(x);
	splay(x);
	zychange(x);
}
void split(int x,int y)
{	
	makeroot(x);
	access(y);
	splay(y);
}
int findroot(int x)
{
	access(x);
	splay(x);
	while(c[x][0])
	{
		put_down(x);
		x=c[x][0];
	}
	return x;
}
void link(int x,int y)
{
	makeroot(x);
	if(findroot(y)!=x)fa[x]=y;
}
void cut(int x,int y)
{
	makeroot(x);
	if(findroot(y)==x&&fa[x]==y&&!c[x][1])
	{
		fa[x]=c[y][0]=0;
		put_up(y);
	}
}
int main()
{
	int n,m;
	int x,y,ch;
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++)scanf("%d",&val[i]);
	while(m--)
	{
		scanf("%d%d%d",&ch,&x,&y);
		if(ch==0)
        {
            split(y,x);
            printf("%d",dis[x]);
            putchar(‘\n‘);
            continue;
        }
        if(ch==1)
        {
            link(x,y);
            continue;
        }
        if(ch==2)
        {
            cut(y,x);
            continue;
        }
        if(ch==3)
        {
            splay(x);
            val[x]=y;
            continue;
        }
	}
}