bzoj 4372 烁烁的游戏 —— 点分治+树状数组

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
using namespace std;
typedef long long ll;
int const xn=1e5+5;
int n,hd[xn],ct,to[xn<<1],nxt[xn<<1],w[xn];
int siz[xn],fa[xn][20],dis[xn][20],dep[xn],mx,rt;
bool vis[xn];
vector<ll>t[xn],fx[xn];
int rd()
{
  int ret=0,f=1; char ch=getchar();
  while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=0; ch=getchar();}
  while(ch>=‘0‘&&ch<=‘9‘)ret=ret*10+ch-‘0‘,ch=getchar();
  return f?ret:-ret;
}
int Max(int x,int y){return x>y?x:y;}
int Min(int x,int y){return x<y?x:y;}
void add(int x,int y){to[++ct]=y; nxt[ct]=hd[x]; hd[x]=ct;}
void getrt(int x,int ff,int sum)
{
  siz[x]=1; int nmx=0;
  for(int i=hd[x],u;i;i=nxt[i])
    {
      if((u=to[i])==ff||vis[u])continue;
      getrt(u,x,sum); siz[x]+=siz[u];
      nmx=Max(nmx,siz[u]);
    }
  nmx=Max(nmx,sum-siz[x]);
  if(nmx<mx)mx=nmx,rt=x;
}
void build(int x,int ff,int d)
{
  for(int i=hd[x],u;i;i=nxt[i])
    {
      if((u=to[i])==ff||vis[u])continue;
      fa[u][++dep[u]]=rt; dis[u][dep[u]]=d;
      build(u,x,d+1);
    }
}
void work(int x,int sum)
{
  vis[x]=1; build(x,0,1);
  t[x].resize(sum+1); fx[x].resize(sum+1);
  for(int i=hd[x],u;i;i=nxt[i])
    {
      if(vis[u=to[i]])continue;
      int ns=(siz[u]>siz[x]?sum-siz[x]:siz[u]);
      mx=xn; getrt(u,0,ns); work(rt,ns);
    }
}
char dc[5];
void ins(int nw,int x,int v){w[nw]+=v; for(x=Min(x,t[nw].size()-1);x;x-=(x&-x))t[nw][x]+=v;}///w[nw]
ll query(int nw,int x){/*if(x==0)return w[nw];*/ ll ret=0; for(;x<t[nw].size()&&x;x+=(x&-x))ret+=t[nw][x]; return ret;}
void ins2(int nw,int x,int v){for(x=Min(x,fx[nw].size()-1);x;x-=(x&-x))fx[nw][x]+=v;}
ll query2(int nw,int x){ll ret=0; for(;x<fx[nw].size()&&x;x+=(x&-x))ret+=fx[nw][x]; return ret;}
ll ask(int x)
{
  ll ret=0;
  for(int i=dep[x];i;i--)
    ret+=query(fa[x][i],dis[x][i])-(i==1?0:query2(fa[x][i],dis[x][i-1]));
  return ret+w[x];
}

void change(int x,int d,int val)
{
  for(int i=dep[x];i;i--)
    {
      //if(d<dis[x][i])continue;
      if(d>=dis[x][i])ins(fa[x][i],d-dis[x][i],val);
      if(d<dis[x][i-1]||i==1)continue;
      ins2(fa[x][i],d-dis[x][i-1],val);//
    }
}
int main()
{
  n=rd(); int m=rd();
  for(int i=1,x,y;i<n;i++)x=rd(),y=rd(),add(x,y),add(y,x);
  mx=xn; getrt(1,0,n); work(rt,n);
  for(int i=1;i<=n;i++)fa[i][++dep[i]]=i;
  for(int i=1,x,d,val;i<=m;i++)
    {
      scanf("%s",dc+1); x=rd();
      if(dc[1]==‘Q‘)printf("%lld\n",ask(x));
      else d=rd(),val=rd(),change(x,d,val);
    }
  return 0;
}