#include<bits/stdc++.h>
using namespace std;
const int N=2e5+10;
#define int long long
#define lc(p) tr[p].ch[0]
#define rc(p) tr[p].ch[1]
#define fa(p) tr[p].f
struct node{int ch[2],f,s,v,sum,tag;}tr[N];
bool notrt(int p){return lc(fa(p))==p||rc(fa(p))==p;}
void pushup(int p){tr[p].s=tr[lc(p)].s+tr[rc(p)].s+tr[p].v+tr[p].sum;}
void pushdown(int p)
{
	if(tr[p].tag)
	{
		swap(lc(p),rc(p));
		tr[lc(p)].tag^=1;tr[rc(p)].tag^=1;
		tr[p].tag=0;
	}
} 
void pushall(int p)
{
	if(notrt(p))pushall(fa(p));
	pushdown(p);
}
void rotate(int x)
{
	int y=fa(x),z=fa(y),k=rc(y)==x;
	if(notrt(y))tr[z].ch[rc(z)==y]=x;fa(x)=z;
	tr[y].ch[k]=tr[x].ch[k^1],fa(tr[x].ch[k^1])=y;
	tr[x].ch[k^1]=y;fa(y)=x;
	pushup(y);pushup(x);
}
void splay(int x)
{
	pushall(x);
	while(notrt(x))
	{
		int y=fa(x),z=fa(y);
		if(notrt(y))((rc(y)==x)^(rc(z)==y))?rotate(x):rotate(y);
		rotate(x);
	}
}
void access(int x)
{
	for(int y=0;x;)
	{
		splay(x);
		tr[x].sum+=tr[rc(x)].s-tr[y].s;
		rc(x)=y;
		pushup(x);
		y=x;x=fa(x);
	}
}
void makert(int x)
{
	access(x);
	splay(x);
	tr[x].tag^=1;
}
void split(int x,int y)
{
	makert(x);
	access(y);
	splay(y);
}
void link(int x,int y)
{
	makert(x);makert(y);
	fa(x)=y;tr[y].sum+=tr[x].s;pushup(y);
}
void cut(int x,int y)
{
	split(x,y);
	fa(x)=lc(y)=0;
}
signed main()
{
	int n,q;cin>>n>>q;
	for(int i=1;i<=n;i++)cin>>tr[i].v;
	for(int i=1;i<n;i++)
	{
		int x,y;cin>>x>>y;x++,y++;
		link(x,y);
	}
	while(q--)
	{
		int op;cin>>op;
		if(op==0)
		{
			int x1,y1,x2,y2;cin>>x1>>y1>>x2>>y2;
			x1++,x2++,y1++,y2++;
			cut(x1,y1);link(x2,y2);
		}
		if(op==1)
		{
			int x,k;cin>>x>>k;x++;
			makert(x);
			tr[x].v+=k;
			pushup(x);
		}
		if(op==2)
		{
			int x,y;cin>>x>>y;x++,y++;
			split(x,y);
			cout<<tr[x].s<<'\n';
		}
	}
	return 0;
}

整 $100$ 行的代码......

#include<bits/stdc++.h>
using namespace std;
#define ll long long
const ll N=2e5+10;
#define lc(p) tr[p].ch[0]
#define rc(p) tr[p].ch[1]
#define fa(p) tr[p].f
struct node{ll ch[2],f,s,v,sum,tag;}tr[N];
bool nl(ll p){return lc(fa(p))==p||rc(fa(p))==p;}
void pushup(ll p){tr[p].s=tr[lc(p)].s+tr[rc(p)].s+tr[p].v+tr[p].sum;}
void pushdown(ll p)
{
	if(tr[p].tag)
	{
		swap(lc(p),rc(p));
		tr[lc(p)].tag^=1;tr[rc(p)].tag^=1;
		tr[p].tag=0;
	}
}
void pushall(ll p)
{
	if(nl(p))pushall(fa(p));
	pushdown(p);
}
void rotate(ll x)
{
	ll y=fa(x),z=fa(y),k=(rc(y)==x);
	if(nl(y))tr[z].ch[rc(z)==y]=x;fa(x)=z;
	tr[y].ch[k]=tr[x].ch[k^1],fa(tr[x].ch[k^1])=y;
	tr[x].ch[k^1]=y;fa(y)=x;
	pushup(y);pushup(x);
}
void splay(ll x)
{
	pushall(x);
	while(nl(x))
	{
		ll y=fa(x),z=fa(y);
		if(nl(y))((rc(y)==x)^(rc(z)==y))?rotate(x):rotate(y);
		rotate(x);
	}
}
void access(ll x)
{
	for(ll y=0;x;y=x,x=fa(x))
	{
		splay(x);
		tr[x].sum+=tr[rc(x)].s-tr[y].s;
		rc(x)=y;
		pushup(x);
	}
}
void makert(ll x)
{
	access(x);splay(x);
	tr[x].tag^=1;
}
void split(ll x,ll y){makert(x);access(y);splay(y);}
void link(ll x,ll y)
{
	makert(x);makert(y);
	fa(x)=y;tr[y].sum+=tr[x].s;
	pushup(y);
}
void cut(ll x,ll y)
{
	split(x,y);
	fa(x)=lc(y)=0;
}
int main()
{
	ll n,q;scanf("%lld%lld",&n,&q);
	for(ll i=1;i<=n;i++)scanf("%lld",&tr[i].v);
	for(ll i=1,x,y;i<n;i++)
	{
		scanf("%lld%lld",&x,&y);
		link(x+1,y+1);
	}
	while(q--)
	{
		ll op,x,y,a,b;scanf("%lld%lld%lld",&op,&x,&y);x++;y++;
		if(!op)
		{
			scanf("%lld%lld",&a,&b);a++;b++;
			cut(x,y);link(a,b);
		}
		else if(op==1)
		{
			makert(x);
			tr[x].v+=y-1;
			pushup(x);
		}
		else
		{
			split(x,y);
			printf("%lld\n",tr[x].s);
		}
	}
	return 0;
}