树链刨分之后很显然就成了一条一条的链
那么用线段树维护一下就行了
#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int n,m,r,pp;
struct e{
int to;
int ne;
int k;
}ed[200005];
int x,y,z,f;
int p;
int head[100005];
int son[100005];
int dep[100005];
int sd[100005];
int siz[100005];
int top[100005];
int fa[100005];
int dfn[100005];
int rnk[100005];
void add(int f,int to){
p++;
ed[p].ne=head[f];
ed[p].to=to;
head[f]=p;
}
int tree[400001];
int lazy[400001];
void pushdown(int R,int l,int r){
if(lazy[R]){
lazy[R<<1]+=lazy[R];
lazy[R<<1|1]+=lazy[R];
int mid= (l+r)>>1;
tree[R<<1]+=lazy[R]*(mid-l+1)%pp;
tree[R<<1|1]+=lazy[R]*(r-mid)%pp;
lazy[R]=0;
}
}
void pushup(int r){
tree[r]=tree[r<<1]+tree[r<<1|1];
}
void add(int root,int L,int R,int l,int r,int v){
if(l<=L&&r>=R){
lazy[root]+=v;
tree[root]+=(R-L+1)*v%pp;
return ;
}
pushdown(root,L,R);
int mid=(L+R)>>1;
if(l<=mid) add(root<<1,L,mid,l,r,v);
if(r>mid) add(root<<1|1,mid+1,R,l,r,v);
pushup(root);
}
int query(int root,int L,int R,int l,int r){
if(l<=L&&r>=R){
return tree[root];
}
int mid=(L+R)>>1,ans=0;
pushdown(root,L,R);
ans%=pp;
if(l<=mid) ans+=query(root<<1,L,mid,l,r)%pp;
ans%=pp;
if(r>mid) ans+=query(root<<1|1,mid+1,R,l,r)%pp;
//pushup(root);
return ans%pp;
}
void dfs(int no,int f){
son[no]=-1;
siz[no]=1;
fa[no]=f;
dep[no]=dep[f]+1;
for(int i=head[no];i;i=ed[i].ne){
if(ed[i].to==f) continue;
dfs(ed[i].to,no);
siz[no]+=siz[ed[i].to];
if(son[no]==-1||siz[ed[i].to]>siz[son[no]]){
son[no]=ed[i].to;
}
}
}
int cnt;
void dfs2(int no,int to){
// cout<<no<<" "<<to<<endl;
cnt++;
dfn[no]=cnt;
top[no]=to;
rnk[cnt]=no;
sd[no]=dfn[no];
if(-1==son[no]) return ;
dfs2(son[no],to);
sd[no]=max(sd[no],sd[son[no]]);
for(int i=head[no];i;i=ed[i].ne){
if(ed[i].to==fa[no]||ed[i].to==son[no]) continue;
dfs2(ed[i].to,ed[i].to);
sd[no]=max(sd[no],sd[ed[i].to]);
}
}
void work1(){
while(top[x]!=top[y]){
if(dep[top[x]]>=dep[top[y]]){
add(1,1,n,dfn[top[x]],dfn[x],z);
x=fa[top[x]];
}else{
add(1,1,n,dfn[top[y]],dfn[y],z);
y=fa[top[y]];
}
}
if(dep[x]>dep[y]){
add(1,1,n,dfn[y],dfn[x],z);
}else{
add(1,1,n,dfn[x],dfn[y],z);
}
}
void work2(){
int ans=0;
while(top[x]!=top[y]){
if(dep[top[x]]>=dep[top[y]]){
ans+=query(1,1,n,dfn[top[x]],dfn[x])%pp;
ans%=pp;
x=fa[top[x]];
}else{
ans+=query(1,1,n,dfn[top[y]],dfn[y])%pp;
ans%=pp;
y=fa[top[y]];
}
}
if(dep[x]>dep[y]){
ans+=query(1,1,n,dfn[y],dfn[x])%pp;
ans%=pp;
}else{
ans+=query(1,1,n,dfn[x],dfn[y])%pp;
ans%=pp;
}
cout<<ans%pp<<endl;
}
int fr[1000001];
int main(){
scanf("%d%d%d%d",&n,&m,&r,&pp);
for(int i=1;i<=n;++i){
scanf("%d",&fr[i]);
}
for(int i=1;i<n;++i){
scanf("%d%d",&x,&y);
add(x,y);
add(y,x);
}
dep[r]=1;
dfs(r,r);
dfs2(r,r);
for(int i=1;i<=n;++i){
add(1,1,n,dfn[i],dfn[i],fr[i]);
}
while(m--){
scanf("%d",&f);
if(f==1){
scanf("%d%d%d",&x,&y,&z);
z%=pp;
work1();
}
if(f==2){
scanf("%d%d",&x,&y);
work2();
}
if(f==3) {
scanf("%d%d",&x,&z);
z%=pp;
add(1,1,n,dfn[x],sd[x],z);
}
if(f==4) {
scanf("%d",&x);
cout<<query(1,1,n,dfn[x],sd[x])%pp<<endl;;
}
}
return 0;
}