【hdu3966】Aragorn's Story

题意：给一棵树，并给定各个点权的值，然后有3种操作：
I C1 C2 K: 把C1与C2的路径上的所有点权值加上K
D C1 C2 K：把C1与C2的路径上的所有点权值减去K
Q C：查询节点编号为C的权值

裸裸的树剖

 #include<algorithm>
 #include<iostream>
 #include<cstdlib>
 #include<cstring>
 #include<cstdio>
 #include<cmath>
 using namespace std;

 typedef long long LL;

 #define N 50010

 struct Node
 {
     int to,next;
 }e[N<<];

 int id,cnt;
 int head[N];
 int num[N],siz[N],top[N],son[N];
 int dep[N],pos[N],rank1[N],fa[N];

 LL sum[N<<],add[N<<];

 char s[];

 int n,m,q;
 int u,v;
 int al,ar,ask;

 inline void init()
 {
     memset(son,-,sizeof(son));
     memset(head,-,sizeof(head));
 id=;
 cnt=;
 }

 void link(int x,int y)
 {
     e[++cnt]=(Node){y,head[x]};
     head[x]=cnt;
 }

 void dfs(int x,int father,int d)
 {
     siz[x]=;
     dep[x]=d;
     fa[x]=father;
     for (int i=head[x];~i;i=e[i].next)
     {
         int t=e[i].to;
         if (t!=fa[x])
         {
             dfs(t,x,d+);
             siz[x]+=siz[t];
             if (son[x]==- || siz[x]>siz[son[x]])
                 son[x]=t;
         }
     }
 }

 void dfs2(int x,int cha)
 {
     top[x]=cha;
     pos[x]=++id;
     rank1[pos[x]]=x;
     if (son[x]==-)
         return ;
     dfs2(son[x],cha);
     for(int i=head[x];~i;i=e[i].next)
     {
         int t=e[i].to;
         if(t!=son[x] && t!=fa[x])
             dfs2(t,t);
     }
 }

 void pushup(int now)
 {
     sum[now]=max(sum[now<<],sum[now<<|]);
 }

 void pushdown(int now,int m)
 {
     if (add[now])
     {
         add[now<<]+=add[now];
         add[now<<|]+=add[now];
         sum[now<<]+=add[now]*(m-(m>>));
         sum[now<<|]+=add[now]*(m>>);
         add[now]=;
     }
 }

 void build(int nowl,int nowr,int now)
 {
     add[now]=;
     if (nowl==nowr)
     {
         sum[now]=num[rank1[nowl]];
         return ;
     }
     int mid=(nowl+nowr)>>;
     build(nowl,mid,now<<);
     build(mid+,nowr,now<<|);
     pushup(now);
 }

 void update(int nowl,int nowr,int now,int L,int R,int d)
 {
     if (nowl>=L && nowr<=R)
     {
         add[now]+=d;
         sum[now]+=d*(nowr-nowl+);
         return ;
     }
     pushdown(now,nowr-nowl+);
     int mid=nowl+nowr>>;
     if (L<=mid) update(nowl,mid,now<<,L,R,d);
     if (mid<R) update(mid+,nowr,now<<|,L,R,d);
     pushup(now);
 }

 int query(int nowl,int nowr,int now,int d)
 {
     int res();
     if (nowl==nowr)
         return sum[now];
     pushdown(now,nowr-nowl+);
     int mid=nowl+nowr>>;
     if (d<=mid) res=query(nowl,mid,now<<,d);
     else res=query(mid+,nowr,now<<|,d);
     pushup(now);
     return res;
 }

 void work(int x,int y,int val)
 {
     while (top[x]!=top[y])
     {
         if (dep[top[x]]<dep[top[y]])
             swap(x,y);
         update(,n,,pos[top[x]],pos[x],val);
         x=fa[top[x]];
     }
     if (dep[x]>dep[y])
         swap(x,y);
     update(,n,,pos[x],pos[y],val);
 }
 int main()
 {
     while (scanf("%d%d%d",&n,&m,&q)!=EOF && n+m+q)
     {
         init();
         for (int i=;i<=n;i++)
             scanf("%d",&num[i]);
         for (int i=;i<=m;i++)
         {
             scanf("%d%d",&u,&v);
             link(u,v);
             link(v,u);
         }
         dfs(,,);
         dfs2(,);
         build(,n,);
         while (q--)
         {
             scanf("%s",s);
             if (s[]=='I')
             {
                 scanf("%d%d%d",&al,&ar,&ask);
                 work(al,ar,ask);
             }
             else if (s[]=='D')
             {
                 scanf("%d%d%d",&al,&ar,&ask);
                 work(al,ar,-ask);
             }
             else
             {
                 scanf("%d",&ask);
                 printf("%d\n",query(,n,,pos[ask]));
             }
         }
     }
     return ;
 }