bzoj1036: [ZJOI2008]树的统计Count

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
using namespace std;
#define rep(i,n) for(int i=1;i<=n;i++)
#define clr(x,c) memset(x,c,sizeof(x))
#define adde(u,v) add(u,v) ,add(v,u)
#define qwq(x) for(edge *o=head[x];o;o=o->next)
#define lson l,m,x<<1
#define rson m+1,r,x<<1|1
int read(){
    int x=0;char c=getchar();bool f=true;
    while(!isdigit(c)) {
        if(c==‘-‘) f=false;c=getchar();
    }
    while(isdigit(c)) x=x*10+c-‘0‘,c=getchar();
    return f?x:-x;
}
const int nmax=30005;
const int inf=0x7f7f7f7f;
struct edge{
    int to;
    edge *next;
};
edge edges[nmax<<1],*pt=edges,*head[nmax];
bool vis[nmax];
int id[nmax],idx[nmax<<2],fa[nmax],size[nmax],son[nmax],dep[nmax],tp[nmax],w[nmax],n;
char ch[100];
struct node{
    int maxn,sum;
};
node tree[nmax<<2];
void add(int s,int t){
    pt->to=t;pt->next=head[s];head[s]=pt++;
}
void dfs(int x){
    vis[x]=1;size[x]=1;
    qwq(x){
        int to=o->to;
        if(!vis[to]){
            dep[to]=dep[x]+1;fa[to]=x;dfs(to);
            size[x]+=size[to];
            if(!son[x]||size[to]>size[son[x]]) son[x]=to;
        }
    }
}
void Dfs(int x,int top){
    id[x]=++id[0];idx[id[0]]=x;tp[x]=top;
    if(son[x]) Dfs(son[x],top);
    qwq(x) if(!id[o->to]) Dfs(o->to,o->to);
}
void pushup(int x){
    node &o=tree[x];node &tl=tree[x<<1];node &tr=tree[x<<1|1];
    o.maxn=max(tl.maxn,tr.maxn);o.sum=tl.sum+tr.sum;
}
void build(int l,int r,int x){
    node &o=tree[x];
    if(l==r) {
        o.maxn=o.sum=w[idx[l]];return ;
    }
    int m=(l+r)>>1;build(lson);build(rson);pushup(x);
}
void update(int p,int add,int l,int r,int x){
    if(l==r) {
        tree[x].maxn=tree[x].sum=add;return ;
    }
    int m=(l+r)>>1;
    p<=m?update(p,add,lson):update(p,add,rson);pushup(x);
}
int querysum(int tl,int tr,int l,int r,int x){
    if(tl<=l&&tr>=r) return tree[x].sum;
    int m=(l+r)>>1;int ans=0;
    if(tl<=m) ans+=querysum(tl,tr,lson);
    if(tr>m) ans+=querysum(tl,tr,rson);
    return ans;
}
int querymax(int tl,int tr,int l,int r,int x){
    if(tl<=l&&tr>=r) return tree[x].maxn;
    int m=(l+r)>>1;int ans=-inf;
    if(tl<=m) ans=max(ans,querymax(tl,tr,lson));
    if(tr>m) ans=max(ans,querymax(tl,tr,rson));
    return ans;
}
int qsum(int a,int b){
    int ans=0;
    while(tp[a]!=tp[b]){
        if(dep[tp[a]]>dep[tp[b]]) swap(a,b);
        ans+=querysum(id[tp[b]],id[b],1,n,1);
        b=fa[tp[b]];
    }
    if(dep[a]>dep[b]) swap(a,b);
    ans+=querysum(id[a],id[b],1,n,1);return ans;
}
int qmax(int a,int b){
    int ans=-inf;
    while(tp[a]!=tp[b]){
        if(dep[tp[a]]>dep[tp[b]]) swap(a,b);
        ans=max(ans,querymax(id[tp[b]],id[b],1,n,1));
        b=fa[tp[b]];
    }
    if(dep[a]>dep[b]) swap(a,b);
    ans=max(ans,querymax(id[a],id[b],1,n,1));return ans;
}
void test(int l,int r,int x){
    if(l==r) printf("%d ",tree[x].maxn);
    else{
        int m=(l+r)>>1;test(lson);test(rson);
    }
}
int main(){
    n=read();
    rep(i,n-1) {
        int s=read(),t=read();adde(s,t);
    }
    /*rep(i,n){
        for(edge *o=head[i];o;o=o->next) printf("%d ",o->to);
        printf("\n");
    }*/
    clr(vis,0);clr(son,0);dep[1]=0;
    clr(id,0);clr(idx,0);id[0]=0;
    dfs(1);Dfs(1,1);
    /*rep(i,n){
        printf("%d:%d %d %d %d\n",i,fa[i],son[i],size[i],dep[i]);
    }*/
    rep(i,n) w[i]=read();
//  rep(i,n) printf("%d ",id[i]);
    build(1,n,1);//test(1,n,1);
    int m=read();
    rep(i,m){
        scanf("%s",ch);int a=read(),b=read();
        if(ch[0]==‘C‘) update(id[a],b,1,n,1);
        else if(ch[1]==‘M‘) printf("%d\n",qmax(a,b));
        else printf("%d\n",qsum(a,b));
    }
    return 0;
}