求条。

#include<bits/stdc++.h>
#define lowbit(x) (x&(-x))
using namespace std;
const int N=1e6+7;
int n,m,idx,opt,u,v,k,head[N],to[N*2],last[N*2],w[N];
int dfn[N],tot,top[N],son[N],sz[N],t[N],dep[N],f[N];
pair<pair<int,int>,pair<int,int> > qus[N];
struct balance_tree{
	vector<int> v,rk;
	int bin_s(int x){
		int l=0,r=rk.size()-1,mid=0,ans=0;
		while(l<=r){
			mid=l+r>>1;
			if(rk[mid]<=x) ans=mid,l=mid+1;
			else r=mid-1;
		}
		return ans;
	}
	void add(int k,int x){
		k=bin_s(k);
		while(k<v.size()) v[k]+=x,k+=lowbit(k);
	}
	int ask(int k){
		k=bin_s(k);
		int res=0;
		while(k) res+=v[k],k-=lowbit(k);
		return res;
	}
}a[N];
inline void add(int u,int v){
	++idx;
	to[idx]=v,last[idx]=head[u],head[u]=idx;
}
inline void dfs(int u,int fa){
	int mx=0;
	sz[u]=1,dep[u]=dep[fa]+1,f[u]=fa;
	for(int i=head[u];i;i=last[i]){
		if(to[i]!=fa){
			dfs(to[i],u),sz[u]+=sz[to[i]];
			if(sz[to[i]]>mx) mx=sz[to[i]],son[u]=to[i];
		}
	}
}
inline void dfs_(int u,int fa,int op){
	dfn[u]=++tot;
	if(op) top[u]=top[fa];
	else top[u]=u;
	for(int i=head[u];i;i=last[i]){
		if(to[i]==son[u]) dfs_(to[i],u,1);
	}
	for(int i=head[u];i;i=last[i]){
		if(to[i]!=fa&&to[i]!=son[u]) dfs_(to[i],u,0);
	}
}
inline void plus_(int k,int x){
	while(k<=n) t[k]+=x,k+=lowbit(k);
}
inline int ask(int k){
	int res=0;
	while(k) res+=t[k],k-=lowbit(k);
	return res;
}
inline void lca(int u,int v,int k,bool op){
	while(top[u]!=top[v]){
		if(dep[top[u]]<dep[top[v]]) swap(u,v);
		if(op){
			a[f[top[u]]].add(ask(dfn[top[u]])
			+w[top[u]],-1);
		}
		plus_(dfn[top[u]],k),plus_(dfn[u]+1,-k);
		if(!op){
			a[f[top[u]]].rk.push_back(ask(dfn[top[u]])
			+w[top[u]]);
		}
		else{
			a[f[top[u]]].add(ask(dfn[top[u]])
			+w[top[u]],1);
		}
		u=f[top[u]];
	}
	if(dep[u]<dep[v]) swap(u,v);
	plus_(dfn[v],k),plus_(dfn[u]+1,-k);
}
int main(){
	ios::sync_with_stdio(0);
	cin.tie(0),cout.tie(0);
	cin>>n>>m;
	for(int i=1;i<=n;i++) cin>>w[i];
	for(int i=1;i<n;i++){
		cin>>u>>v;
		add(u,v),add(v,u);
	}
	dfs(1,0),dfs_(1,0,0);
	for(int i=1;i<=n;i++){
		a[i].rk.clear(),a[i].v.clear();
		a[i].rk.push_back(0),a[i].v.push_back(0);
		a[i].rk.push_back(w[i]),a[i].v.push_back(0);
		for(int j=head[i];j;j=last[j]){
			a[i].rk.push_back(w[to[j]]);
			a[i].v.push_back(0);
		}
	}
	for(int i=1;i<=m;i++){
		cin>>opt>>u;
		if(opt==1){
			cin>>v>>k,qus[i]={{opt,u},{v,k}};
			lca(u,v,k,0);
		}
		else{
			cin>>k,qus[i]={{opt,u},{0,k}};
			if(son[u]){
				a[u].rk.push_back(ask(dfn[son[u]])
				+w[son[u]]);
			}
			if(f[u]) a[u].rk.push_back(ask(dfn[f[u]])+w[f[u]]);
			a[u].rk.push_back(ask(dfn[u])+w[u]);
		}
	}
	for(int i=1;i<=n;i++){
		sort(a[i].rk.begin(),a[i].rk.end());
		while(a[i].v.size()<a[i].rk.size()) a[i].v.push_back(0);
 		for(int j=head[i];j;j=last[j]){
			if(to[j]!=f[i]&&to[j]!=son[i]){
				a[i].add(w[to[j]],1);
			}
		}
		t[i]=0;
	}
	/*for(int i=0;i<11;i++) cout<<a[1].v[i]<<" ";
	cout<<'\n'<<a[1].ask(5);*/
	
	for(int i=1;i<=m;i++){
		opt=qus[i].first.first;
		u=qus[i].first.second;
		v=qus[i].second.first;
		k=qus[i].second.second;
		if(opt==1) lca(u,v,k,1);
		else{
			if(son[u]){
				a[u].add(ask(dfn[son[u]])+w[son[u]],1);
			}
			if(f[u]) a[u].add(ask(dfn[f[u]])+w[f[u]],1);
			a[u].add(ask(dfn[u])+w[u],1);
			int l=0,r=a[u].rk.size()-1,mid=0,ans=0;
			while(l<=r){
				mid=l+r>>1;
				if(a[u].ask(a[u].rk[mid])>=k) ans=a[u].rk[mid],r=mid-1;
				else l=mid+1;
			}
			cout<<ans<<'\n';
			if(son[u]){
				a[u].add(ask(dfn[son[u]])+w[son[u]],-1);
			}
			if(f[u]) a[u].add(ask(dfn[f[u]])+w[f[u]],-1);
			a[u].add(ask(dfn[u])+w[u],-1);
		}
		
	}
	return 0;
}