刚学oi就红名的蒟蒻求救

看提交记录里面很多人都是31分诶，肯定有一个坑！但是我不知道诶

#include<bits/stdc++.h>
using namespace std;
#define loop(i,start,end) for(register int i=start;i<=end;++i)
#define anti_loop(i,start,end) for(register int i=start;i>=end;--i)
#define clean(arry,num); memset(arry,num,sizeof(arry));
#define max(a,b) ((a>b)?a:b)
#define min(a,b) ((a<b)?a:b)
#define asc(a) (a-'A')
#define ll long long
const int maxn=1e6+10,maxm=1e6+10;
int n,m,cnt=0;
struct node{
    int e;int nxt;
}edge[maxn<<1];
int head[maxn];
int dep[maxn],son[maxn],siz[maxn],fa[maxn];
int seg[maxn],rev[maxn],top[maxn];
ll lazy[maxn<<2],sum[maxn<<2];
inline void addl(int u,int v){
    edge[cnt].e=v;
    edge[cnt].nxt=head[u];
    head[u]=cnt++;
}
void dfs1(int u,int f){
    dep[u]=dep[f]+1;
    fa[u]=f;siz[u]=1;
    for(int i=head[u];i!=-1;i=edge[i].nxt){
        int v=edge[i].e;
        if(v==f)continue;
        dfs1(v,u);
        siz[u]+=siz[v];
        if(siz[son[u]]<siz[v])son[u]=v;
    }
}
void dfs2(int u,int fa){
    if(son[u]){
        seg[son[u]]=++seg[0];
        rev[seg[0]]=son[u];
        top[son[u]]=top[u];
        dfs2(son[u],u);
    }
    for(int i=head[u];i!=-1;i=edge[i].nxt){
        int v=edge[i].e;
        if(!top[v]){
            top[v]=v;
            seg[v]=++seg[0];
            rev[seg[0]]=v;
            dfs2(v,u);
        }
    }
}
inline void buildtree(){clean(lazy,0);clean(sum,0);}
inline void pushup(int rt){sum[rt]=sum[rt<<1]+sum[rt<<1|1];}
inline void pushdown(int rt,int l,int r){
    if(!lazy[rt])return;
    int mid=(l+r)>>1;
    lazy[rt<<1]+=lazy[rt];
    lazy[rt<<1|1]+=lazy[rt];
    sum[rt<<1]+=lazy[rt]*(mid-l+1);
    sum[rt<<1|1]+=lazy[rt]*(r-(mid+1)+1);
    lazy[rt]=0;
}
void update(int l,int r,int nl,int nr,int rt,int w){
    if(l<=nl&&nr<=r){
        lazy[rt]+=w;
        sum[rt]+=w*(nr-nl+1);
        return;
    }
    pushdown(rt,nl,nr);
    int mid=((nr+nl)>>1);
    if(mid>=l)update(l,r,nl,mid,rt<<1,w);
    if(mid<r)update(l,r,mid+1,nr,rt<<1|1,w);
    pushup(rt);
}
ll query(int l,int r,int nl,int nr,int rt){
    if(l<=nl&&nr<=r)return sum[rt];
    int mid=(nr+nl)>>1;
    ll _sum=0;
    if(mid>=l)_sum+=query(l,r,nl,mid,rt<<1);
    if(mid<r)_sum+=query(l,r,mid+1,nr,rt<<1|1);
    return _sum;
}
inline void updateline(int x,int y,int w){
    int fx=top[x],fy=top[y];
    while(fx!=fy){
        if(dep[fx]<dep[fy])swap(fx,fy),swap(x,y);
        update(seg[fx],seg[x],1,seg[0],1,w);
        x=fa[fx];fx=top[x];
    }
    if(dep[x]<dep[y])swap(x,y);
    //update(seg[y],seg[x],1,seg[0],1,w);
    update(seg[y]+1,seg[x],1,seg[0],1,w);
}

inline ll queryline(int x,int y){
    int fx=top[x],fy=top[y];
    ll _sum=0;
    while(fx!=fy){
        if(dep[fx]<dep[fy])swap(fx,fy),swap(x,y);
        _sum+=query(seg[fx],seg[x],1,seg[0],1);
        x=fa[fx],fx=top[x];
    }
    if(dep[x]<dep[y])swap(x,y);
    //_sum+=query(seg[y],seg[x],1,seg[0],1);
    _sum+=query(seg[y]+1,seg[x],1,seg[0],1);
    return _sum;
}/*
inline ll queryline(int x,int y){
    int _p=((dep[x]<dep[y])?y:x);
    return query(seg[_p],seg[_p],1,seg[0],1);
}*/
inline void rep(){
    register char op[100];
    loop(i,1,m){
        scanf("%s",op);
        if(op[0]=='P'){
            int xi,yi;
            scanf("%d%d",&xi,&yi);
            updateline(xi,yi,1);
        }
        else if(op[0]=='Q'){
            int xi,yi;
            scanf("%d%d",&xi,&yi);
            printf("%lld\n",queryline(xi,yi));
        }
    }
}
int main(){
    #ifndef ONLINE_JUDGE
    freopen("datain.txt","r",stdin);
    #endif // ONLINE_JUDGE
    scanf("%d%d",&n,&m);
    clean(head,-1);
    loop(i,1,n){
        int xi,yi;
        scanf("%d%d",&xi,&yi);
        addl(xi,yi),addl(yi,xi);
    }
    dfs1(1,0);
    seg[1]=seg[0]=rev[1]=top[1]=1;
    dfs2(1,0);
    //#ifdef ONLtINE_JUDGE
    //freopen("CON","r",stdin);
    //m=INT_MAX;
    //#endif // ONLINE_JUDGE
    rep();
    return 0;
}