bzoj1036: [ZJOI2008]树的统计Count 树链剖分+线段树

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/**************************************************************
    Problem: 1036
    User: 96655
    Language: C++
    Result: Accepted
    Time:2472 ms
    Memory:5536 kb
****************************************************************/

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<string>
#include<iostream>
#include<cstdlib>
#include<queue>
#include<map>
#include<set>
#include<vector>
#include<cmath>
#include<stack>
#include<utility>
using namespace std;
const int maxn=;
struct Edge
{
    int v,next;
} edge[maxn*];
int va[maxn],p,head[maxn],clk,n;
void init()
{
    memset(head,-,sizeof(head));
    p=clk=;
}
void addedge(int u,int v)
{
    edge[p].v=v;
    edge[p].next=head[u];
    head[u]=p++;
}
int id[maxn],sz[maxn],dep[maxn],fa[maxn],son[maxn],top[maxn];
int xx[maxn];
void dfs1(int u,int f,int d)
{
    dep[u]=d;
    fa[u]=f;
    sz[u]=;
    son[u]=-;
    for(int i=head[u]; ~i; i=edge[i].next)
    {
        int v=edge[i].v;
        if(v==f)continue;
        dfs1(v,u,d+);
        sz[u]+=sz[v];
        if(son[u]==-||sz[v]>sz[son[u]])
            son[u]=v;
    }
}
void dfs2(int u,int tp)
{
    id[u]=++clk;
    xx[id[u]]=va[u];
    top[u]=tp;
    if(son[u]!=-)dfs2(son[u],tp);
    for(int i=head[u]; ~i; i=edge[i].next)
    {
        int v=edge[i].v;
        if(v==fa[u]||v==son[u])continue;
        dfs2(v,v);
    }
}
int sum[maxn*],maxv[maxn*];
void pushup(int rt)
{
    sum[rt]=sum[rt*]+sum[rt*+];
    maxv[rt]=max(maxv[rt*],maxv[rt*+]);
}
void build(int rt,int l,int r)
{
    if(l==r)
    {
        sum[rt]=maxv[rt]=xx[l];
        return;
    }
    int m=(l+r)>>;
    build(rt*,l,m);
    build(rt*+,m+,r);
    pushup(rt);
}
void update(int rt,int l,int r,int pos,int c)
{
    if(l==r)
    {
        maxv[rt]=sum[rt]=c;
        return;
    }
    int m=(l+r)>>;
    if(pos<=m)update(rt*,l,m,pos,c);
    else update(rt*+,m+,r,pos,c);
    pushup(rt);
}
int query1(int rt,int l,int r,int x,int y)
{
    if(x<=l&&r<=y)
    {
        return sum[rt];
    }
    int ans=;
    int m=(l+r)>>;
    if(x<=m)ans+=query1(rt*,l,m,x,y);
    if(y>m)ans+=query1(rt*+,m+,r,x,y);
    return ans;
}
int query2(int rt,int l,int r,int x,int y)
{
    if(x<=l&&r<=y)
    {
        return maxv[rt];
    }
    int ans=-;
    int m=(l+r)>>;
    if(x<=m)ans=max(ans,query2(rt*,l,m,x,y));
    if(y>m)ans=max(ans,query2(rt*+,m+,r,x,y));
    return ans;
}
int getsum(int u,int v)
{
    int ans=;
    while(top[u]!=top[v])
    {
        if(dep[top[u]]<dep[top[v]])
            swap(u,v);
        ans+=query1(,,n,id[top[u]],id[u]);
        u=fa[top[u]];
    }
    if(dep[u]>dep[v])swap(u,v);
    ans+=query1(,,n,id[u],id[v]);
    return ans;
}
int getmax(int u,int v)
{
    int ans=-;
    while(top[u]!=top[v])
    {
        if(dep[top[u]]<dep[top[v]])
            swap(u,v);
        ans=max(ans,query2(,,n,id[top[u]],id[u]));
        u=fa[top[u]];
    }
    if(dep[u]>dep[v])swap(u,v);
    ans=max(ans,query2(,,n,id[u],id[v]));
    return ans;
}
int main()
{
    while(~scanf("%d",&n))
    {
        init();
        for(int i=; i<n; ++i)
        {
            int u,v;
            scanf("%d%d",&u,&v);
            addedge(u,v);
            addedge(v,u);
        }
        for(int i=; i<=n; i++)
            scanf("%d",&va[i]);
        dfs1(,,);
        dfs2(,);
        build(,,n);
        int q;
        scanf("%d",&q);
        while(q--)
        {
            char s[];
            int x,y;
            scanf("%s%d%d",s,&x,&y);
            if(s[]=='Q')
            {
                if(s[]=='M') printf("%d\n",getmax(x,y));
                else printf("%d\n",getsum(x,y));
            }
            else update(,,n,id[x],y);
        }
    }
    return ;
}