不知道哪错了

#include <bits/stdc++.h>
using namespace std;
#define reg register
#define len(x) (node[x].r-node[x].l+1)
inline int read()
{
    int x=0,f=1;
    char ch=getchar();
    while(!isdigit(ch))
    {
        if(ch=='-')f=-1;
        ch=getchar();
    }
    while(isdigit(ch))
    {
        x=(x<<1)+(x<<3)+(ch^48);
        ch=getchar();
    }
    return x*f;
}
const int maxn=1e5+5;
int n,m,rt,p;
//----------make_graph------------
struct EDGE
{
    int to,nxt;
}edge[maxn<<1];
int nxt[maxn<<1];
int head[maxn<<1];
int tot;
inline void add(int u,int to)
{
    edge[++tot].to=to;
    edge[tot].nxt=head[u];
    head[u]=tot;
}
//-------------tree---------
struct Node
{
    int val,lazy,l,r,ls,rs;
}node[maxn];
int val[maxn];//题目给定点权
int dfn[maxn];//当前节点的dfs序
int hs[maxn];//当前节点的重儿子
int noderank[maxn];//第i个访问到的节点是谁
int nodesize[maxn];//当前节点为根的子树的大小
int dep[maxn];//当前节点深度
int top[maxn];//当前节点的链顶
int cnt;
int father[maxn];
void dfs1(int x)
{
    cout<<"x: "<<x<<endl;
    nodesize[x]=1;
    dep[x]=dep[father[x]]+1;
    for(int i=head[x];i;i=edge[i].nxt)
    {
        reg int to=edge[i].to;
        if(to==father[x])continue;
        father[to]=x;
        dfs1(to);
        nodesize[x]+=nodesize[to];
        if(nodesize[to]>=nodesize[hs[x]])
        {
            hs[x]=to;
        }
    }
}
void dfs2(int x,int tp)
{
    cout<<"x: "<<x<<endl;
    dfn[x]=++cnt;
    noderank[cnt]=x;
    top[x]=tp;
    if(hs[x])
        dfs2(hs[x],tp);
    for(int i=head[x];i;i=edge[i].nxt)
    {
        reg int to=edge[i].to;
        if(to==hs[x]||to==father[x])continue;
        dfs2(to,to);
    }
}
inline void push_up(int x)
{
    node[x].val=(node[node[x].ls].val+node[node[x].rs].val)%p;
}
void Build(int x,int l,int r)
{
    if(l==r)
    {
        node[x].val=val[noderank[l]]%p;
        node[x].l=node[x].r=l;
        return;
    }
    node[x].ls=++cnt;
    node[x].rs=++cnt;
    int mid=(l+r)>>1;
    Build(node[x].ls,l,mid);
    Build(node[x].rs,mid+1,r);
    push_up(x);
}
inline void pushdown(int x)
{
    if(!node[x].lazy)return;
    node[node[x].ls].lazy+=node[x].lazy;
    node[node[x].rs].lazy+=node[x].lazy;
    node[node[x].ls].lazy%=p;
    node[node[x].rs].lazy%=p;
    node[node[x].ls].val+=(len(node[x].ls)*(node[node[x].ls].lazy));
    node[node[x].rs].val+=(len(node[x].rs)*(node[node[x].rs].lazy));
    node[node[x].ls].val%=p;
    node[node[x].rs].val%=p;
    node[x].lazy=0;
}
void update(int x,int l,int r,int c)
{//对线段树某一区间修改
    if(node[x].l>=l&&node[x].r<=r)
    {
        node[x].lazy+=c;
        return;
    }
    pushdown(x);
    int mid=(node[x].l+node[x].r)>>1;
    if(mid>=l)update(node[x].ls,l,r,c);
    if(mid<r)update(node[x].rs,l,r,c);
    push_up(x);
}
int query(int x,int l,int r)
{//对线段树某一区间修改
    if(node[x].l>=l&&node[x].r<=r)
    {
        return node[x].val%p;
    }
    pushdown(x);
    int ans=0;
    //cout<<"l: "<<l<<" r: "<<r<<endl;
    int mid=(node[x].l+node[x].r)>>1;
    if(mid>=l)ans+=query(node[x].ls,l,r);
    if(mid<r)ans+=query(node[x].rs,l,r);
    return ans%p;
}
int get_sum(int x,int y)
{
    int ans=0;
    while(top[x]!=top[y])
    {
        if(dep[x]<dep[y])swap(x,y);
        ans+=query(1,dfn[top[x]],dfn[x])%p;      
        x=father[top[x]]; 
    }
    if(dfn[x]>dfn[y])swap(x,y);
    ans+=query(1,dfn[x],dfn[y])%p;
    return ans%p;
}
void updates(int x,int y,int z)
{
    while(top[x]!=top[y])
    {
        if(dep[x]<dep[y])swap(x,y);
        update(1,dfn[top[x]],dfn[x],z);      
        x=father[top[x]]; 
    }
    if(dfn[x]>dfn[y])swap(x,y);
    update(1,dfn[x],dfn[y],z);
}
//--------------main-------
int main()
{
    n=read();
    m=read();
    rt=read();
    p=read();
    for(reg int i=1;i<=n;i++)val[i]=read();
    reg int x,y;
    for(reg int i=1;i<n;i++)
    {
        x=read();
        y=read();
        add(x,y);
        add(y,x);
    }
    dfs1(rt);
    dfs2(rt,rt);
    cnt=1;
    Build(cnt,1,n);
    int op,z;
    for(reg int i=1;i<=m;i++)
    {
        op=read();
        if(op==1)
        {
            x=read();
            y=read();
            z=read();
            updates(x,y,z);
        }
        if(op==2)
        {
            x=read();
            y=read();
            printf("%d\n",get_sum(x,y));
        }
        if(op==3)
        {
            x=read();
            z=read();
            update(1,dfn[x],dfn[x]+nodesize[x]-1,z);
        }
        if(op==4)
        {
            x=read();
            printf("%d\n",query(1,dfn[x],dfn[x]+nodesize[x]-1));
        }
    }
    #ifndef ONLINE_JUDGE
    system("pause");
    #endif
    return 0;
}