BZOJ 1036 [ZJOI2008] 树的统计Count (树链剖分)

#include <iostream>
#include <string.h>
#include <math.h>
#include <queue>
#include <algorithm>
#include <stdlib.h>
#include <map>
#include <set>
#include <stdio.h>
using namespace std;
#define LL long long
#define pi acos(-1.0)
//#pragma comment(linker, "/STACK:1024000000")
const int mod=1e9+7;
const int INF=0x3f3f3f3f;
const double eqs=1e-3;
const int MAXN=30000+10;
#define root 1, tot, 1
#define lson l, mid, rt<<1
#define rson mid+1, r, rt<<1|1

int head[MAXN], cnt, tot;
int siz[MAXN], top[MAXN], fa[MAXN], w[MAXN], son[MAXN], dep[MAXN];
int Max[MAXN<<2], sum[MAXN<<2];
struct node
{
int v, next;
}edge[MAXN<<1];
void add(int u, int v)
{
edge[cnt].v=v;
edge[cnt].next=head[u];
head[u]=cnt++;
}
void init()
{
memset(head,-1,sizeof(head));
cnt=tot=0;
memset(dep,0,sizeof(dep));
memset(son,0,sizeof(son));
memset(Max,-INF,sizeof(Max));
memset(sum,0,sizeof(sum));
}
void dfs1(int u, int p)
{
siz[u]=1;
for(int i=head[u];i!=-1;i=edge[i].next){
int v=edge[i].v;
if(v==p) continue ;
dep[v]=dep[u]+1;
fa[v]=u;
dfs1(v,u);
siz[u]+=siz[v];
if(siz[son[u]]<siz[v]) son[u]=v;
}
}
void dfs2(int u, int tp)
{
w[u]=++tot;
top[u]=tp;
if(son[u]) dfs2(son[u],tp);
for(int i=head[u];i!=-1;i=edge[i].next){
int v=edge[i].v;
if(v!=fa[u]&&v!=son[u])
dfs2(v,v);
}
}
struct Line_Tree
{
void PushUp(int rt)
{
Max[rt]=max(Max[rt<<1],Max[rt<<1|1]);
sum[rt]=sum[rt<<1]+sum[rt<<1|1];
}
void Update(int p, int x, int l, int r, int rt)
{
if(l==r){
Max[rt]=sum[rt]=x;
return ;
}
int mid=l+r>>1;
if(p<=mid) Update(p,x,lson);
else Update(p,x,rson);
PushUp(rt);
}
int MaxQuery(int ll, int rr, int l, int r, int rt)
{
if(ll<=l&&rr>=r){
return Max[rt];
}
int mid=l+r>>1, ans=-INF;
if(ll<=mid) ans=max(ans,MaxQuery(ll,rr,lson));
if(rr>mid) ans=max(ans,MaxQuery(ll,rr,rson));
return ans;
}
int SumQuery(int ll, int rr, int l, int r, int rt)
{
if(ll<=l&&rr>=r){
return sum[rt];
}
int mid=l+r>>1, ans=0;
if(ll<=mid) ans+=SumQuery(ll,rr,lson);
if(rr>mid) ans+=SumQuery(ll,rr,rson);
return ans;
}
}lt;
int MaxSolve(int u, int v)
{
int f1=top[u], f2=top[v], ans=-INF;
while(f1!=f2){
if(dep[f1]<dep[f2]){
swap(u,v);
swap(f1,f2);
}
ans=max(ans,lt.MaxQuery(w[f1],w[u],root));
u=fa[f1];f1=top[u];
}
if(dep[u]<dep[v]){
swap(u,v);
}
return max(ans,lt.MaxQuery(w[v],w[u],root));
}
int SumSolve(int u, int v)
{
int f1=top[u], f2=top[v], ans=0;
while(f1!=f2){
if(dep[f1]<dep[f2]){
swap(u,v);
swap(f1,f2);
}
ans+=lt.SumQuery(w[f1],w[u],root);
u=fa[f1];f1=top[u];
}
if(dep[u]<dep[v]){
swap(u,v);
}
return ans+lt.SumQuery(w[v],w[u],root);
}
int main()
{
int n, i, u, v, c, q, id;
char s[10];
while(scanf("%d",&n)!=EOF){
init();
for(i=1;i<n;i++){
scanf("%d%d",&u,&v);
add(u,v);
add(v,u);
}
dfs1(1,-1);
dfs2(1,1);
for(i=1;i<=n;i++){
scanf("%d",&c);
lt.Update(w[i],c,root);
}
scanf("%d",&q);
while(q--){
scanf("%s",s);
if(s[1]=='M'){
scanf("%d%d",&u,&v);
printf("%d\n",MaxSolve(u,v));
}
else if(s[1]=='S'){
scanf("%d%d",&u,&v);
printf("%d\n",SumSolve(u,v));
}
else{
scanf("%d%d",&id,&c);
lt.Update(w[id],c,root);
}
}
}
return 0;
}