#include <iostream>

#define ls(x) (s[x].ch[0])
#define rs(x) (s[x].ch[1])
#define fa(x) (s[x].fa)
#define son(x,f) (rs(f)==x)
#define conn(x,f,k) s[fa(x)=f].ch[k]=x 
#define upd(x) s[x].sum=s[ls(x)].sum^s[rs(x)].sum^s[x].val
#define nrt(x) (ls(fa(x))==x or rs(fa(x))==x)
#define rota(x) swap(ls(x),rs(x)),s[x].rev^=1

using namespace std;

const int N=3E5+5;
struct node {
	int ch[2];
	int fa;
	int val,siz;
	bool rev;
	int sum;
}s[N];
int st[N];
inline int pu(int p) {
	if(s[p].rev) {
		rota(ls(p));
		rota(rs(p));
	}
	s[p].rev=false;
}

inline void pushall(int p) {
	int top=0;
	while(nrt(p)) {
		st[++top]=p;
	  	p=fa(p);
	}
	pu(p);
	while(top)
	  pu(st[top--]);
}

inline void rot(int p) {
	int f=fa(p),ff=fa(f),k=son(p,f);
	conn(s[p].ch[k^1],f,k);
	fa(p)=ff;
	if(nrt(f))
	  s[ff].ch[son(f,ff)]=p;
	conn(f,p,k^1);
	upd(f);
	upd(p);
}

inline void splay(int p) {
	pushall(p);
	while(nrt(p)) {
		int f=fa(p),ff=fa(f);
		if(nrt(f))
		  son(f,ff)^son(p,f)?rot(p):rot(f);
		rot(p);
	}
}

inline void access(int p) {
	for(int y=0;p;p=fa(y=p)) {
		splay(p);
		rs(p)=y;
		upd(p);
	}
}

inline void mkrot(int p) {
	access(p);
	splay(p);
	rota(p);
}

inline int findrot(int p) {
	access(p);
	splay(p);
	while(ls(p)) {
		pu(p);
		p=ls(p);
	}
	splay(p);
	return p;
}

inline void lnk(int x,int y) {
	mkrot(x);
	if(findrot(y)==x)
	  return ;
	fa(x)=y;
}

inline void cut(int x,int y) {
	mkrot(x);
	if(fa(y)!=x or findrot(y)!=x or ls(y))
	  return ;
	rs(x)=fa(y)=0;
	upd(x);
}

inline void split(int x,int y) {
	mkrot(x);
	access(y);
	splay(y);
}

int main() {
	int n,m;
	cin>>n>>m;
	for(int i=1;i<=n;i++)
	  cin>>s[i].val;
	while(m--) {
		int opt,x,y;
		cin>>opt>>x>>y;
		if(opt==0) {
			split(x,y);
			cout<<s[y].sum<<endl;
		}
		if(opt==1) 
		  lnk(x,y);
		if(opt==2)
		  cut(x,y);
		if(opt==3) {
			splay(x);
			s[x].val=y;
			upd(x);
		}
	}
	return 0;
}

第一个点下载下来看了，是通过的，但是到了洛谷就全RE了