改了一遍，但还是有问题
```
#include<bits/stdc++.h>
using namespace std;
vector<int> g[114514];
int n,p,cnt,w[114514],fa[114514],dep[114514],val[114514],son[114514],dfn[114514],rk[114514],top[114514];
long long lazy1[114514],lazy2[114514];
int lowbit(int x)
{
return x&(-x);
}
void add(int l,int r,int x)
{
x%=p;
int add1=(long long)(l-1)*x%p,add2=(long long)r*x%p;
for(int i=l;i<=n;i+=lowbit(i))
{
lazy1[i]+=x;
lazy1[i]%=p;
lazy2[i]+=add1;
lazy2[i]%=p;
}
for(int i=r+1;i<=n;i+=lowbit(i))
{
lazy1[i]-=x;
lazy1[i]%=p;
lazy1[i]+=p;
lazy1[i]%=p;
lazy2[i]-=add2;
lazy2[i]%=p;
}
}
int cg(int x)
{
int res=0;
for(int i=x;i>0;i-=lowbit(i))
{
res+=((long long)x*lazy1[i]%p);
res%=p;
res-=lazy2[i];
res%=p;
res+=p;
res%=p;
}
return res;
}
int query(int l,int r)
{
int res=(cg(r)-cg(l-1))%p;
return (res+p)%p;
}
void dfs1(int u,int f,int d)
{
fa[u]=f;
dep[u]=d;
val[u]=1;
son[u]=0;
for(int i=0;i<g[u].size();i++)
{
int v=g[u][i];
if(f==v)continue;
dfs1(v,u,d+1);
val[u]+=val[v];
if(val[v]>val[son[u]])son[u]=v;
}
}
void dfs2(int u,int topfa)
{
dfn[u]=++cnt;
rk[cnt]=u;
top[u]=topfa;
if(g[u].size()==0)return;
dfs2(son[u],topfa);
for(int i=0;i<g[u].size();i++)
{
int v=g[u][i];
if(v==fa[u]||v==son[u])continue;
dfs2(v,v);
}
}
void addpath(int u,int v,int k)
{
while(top[u]!=top[v])
{
if(dep[top[u]]<dep[top[v]])swap(u,v);
add(dfn[top[u]],dfn[u],k);
u=fa[top[u]];
}
if(dep[u]>dep[v])swap(u,v);
add(dfn[u],dfn[v],k);
}
int querypath(int u,int v)
{
int res=0;
while(top[u]!=top[v])
{
if(dep[top[u]]<dep[top[v]])swap(u,v);
res+=query(dfn[top[u]],dfn[u]);
res%=p;
u=fa[top[u]];
}
if(dep[u]>dep[v])swap(u,v);
res+=query(dfn[u],dfn[v]);
res%=p;
return res;
}
int main()
{
int m,r,op,x,y,z;
cin>>n>>m>>r>>p;
for(int i=1;i<=n;i++)cin>>w[i];
for(int i=1;i<n;i++)
{
cin>>x>>y;
g[x].push_back(y);
g[y].push_back(x);
}
dfs1(r,0,0);
dfs2(r,r);
for(int i=0;i<m;i++)
{
cin>>op>>x;
if(op==1)
{
cin>>y>>z;
z%=p;
addpath(x,y,z);
}
if(op==2)
{
cin>>y;
cout<<querypath(x,y)<<'\n';
}
if(op==3)
{
cin>>z;
z%=p;
add(dfn[x],dfn[x]+val[x]-1,z);
}
if(op==4)cout<<query(dfn[x],dfn[x]+val[x]-1)<<'\n';
}
return 0;
}
```
by Bernie_qwq @ 2023-02-15 17:03:48