rt，错误原因是 $qry$ 时一直在跳，但我不知道为啥，所以求调

#include <bits/stdc++.h>
using namespace std;

inline int read() {
	int x=0,f=1;char ch=getchar();
	while (ch<'0'||ch>'9'){if (ch=='-') f=-1;ch=getchar();}
	while (ch>='0'&& ch<='9'){x=x*10+ch-48;ch=getchar();}
	return x*f;
}
const int N = 5e5 + 10, M = 19, K = 5e6 + 10, inf = 1e9;
int n,m,a[N],dfn[N],dep[N],cnt,mn[M][N],fa[N];
vector<int> e[N];
inline void add(int u,int v){
	e[u].push_back(v);
} 
inline int calc(int x,int y){
	return dfn[x] < dfn[y] ? x : y;
}
void dfs(int u,int fa){
	dep[u]=dep[fa]+1;
 	mn[0][dfn[u]=++cnt]=fa;
	for (auto v:e[u]){
		if (v==fa) continue;
		dfs(v,u);
	}
}

int siz[N],vis[N],mx[N],rt;
int calcrt(int u,int fa,int tot){
	siz[u]=1,mx[u]=0;
	for (auto v:e[u]){
		if (v==fa || vis[v]) continue;
		calcrt(v,u,tot);
		siz[u]+=siz[v];
		mx[u]=max(mx[u],siz[v]);
	}
	mx[u]=max(mx[u],tot-siz[u]);
	if (mx[u]<mx[rt]) rt=u;
}
void build(int u,int tot){
	vis[u]=1;
	for (auto v:e[u]){
		if (vis[v]) continue;
		rt=0;
		int p=(siz[v]<siz[u])?siz[u]:(tot-siz[u]);
		calcrt(v,u,p);
		fa[rt]=u;
		build(rt,p);
	}
}
void init(){
	for (int i=1;i<=18;i++){
		for (int j=1;j<=n;j++){
			mn[i][j]=calc(mn[i-1][j],mn[i-1][j+(1<<i-1)]);
		}
	}	
}
inline int lca(int u,int v){
  	if(u==v) return u;
  	if((u=dfn[u])>(v=dfn[v])) swap(u,v);
  	int d=__lg(v-u++);
  	return calc(mn[d][u],mn[d][v-(1<<d)+1]);
}
inline int dis(int x,int y){
	return dep[x]+dep[y]-(dep[lca(x,y)]<<1);
}
struct segment{
	int rt[N],lc[K],rc[K],w[K];
	inline void pushup(int p){
		w[p]=w[lc[p]]+w[rc[p]];
	}
	void ins(int &p,int l,int r,int v,int k){
	    if(!p) p=++cnt;
	    if(l==r){w[p]+=k;return ;}
		int mid=l+r>>1;
    	if(v<=mid) ins(lc[p],l,mid,v,k);
		else ins(rc[p],mid+1,r,v,k);
		pushup(p);
	}
	int qry(int p,int cl,int cr,int l,int r){
		if(!p || cr<l || cl>r) return 0;
		if(l<=cl && cr<=r) return w[p];
		int mid=cl+cr>>1;
		return qry(lc[p],cl,mid,l,r)+qry(rc[p],mid+1,cr,l,r);
	}	
}t1,t2;

void ins(int u,int w){
	int v=u;
	while(u){
		t1.ins(t1.rt[u],1,n,dis(u,v),w);
		if(fa[u]) t2.ins(t2.rt[u],1,n,dis(u,fa[u]),w);
		u=fa[u];
	}
}
int qry(int u,int k){
	int v=u,son=0,res=0;
	while(u){
		if(dis(u,v)>k){
			son=u;
			u=fa[u];
//			printf("%d\n",u);
			continue;
		}
//		printf("%d\n",u);
		res+=t1.qry(t1.rt[u],1,n,1,k-dis(u,v));
		if(son) res-=t2.qry(t2.rt[son],1,n,1,k-dis(u,v));
		son=u;
		u=fa[u];
	} 
	return res;
}
signed main(){
	、、freopen("P6329_1.in","r",stdin);
	n=read(),m=read();
	for(int i=1;i<=n;i++){
		a[i]=read();
	}
	for(int i=1;i<=n-1;i++){
		int u=read(),v=read();
		add(u,v),add(v,u);
	} 
	
	dfs(1,0);
	init(); 
	rt=0;
	mx[rt]=inf;
	calcrt(1,0,n);
	build(rt,n);
	
	for(int i=1;i<=n;i++){
		ins(i,a[i]);
	}
	int x=0;
	while(m--){
		int opr=read(),u=read()^x,k=read()^x;
		if(opr==0){
			printf("%d\n",x=qry(u,k));
		}
		else{
			ins(x,k-a[u]);
			a[u]=k;
		}
	}	
  	return 0;
}