[点分树 二分答案] BZOJ 2117 [2010国家集训队]Crash的旅游计划

二分答案后就转化为有多少个数到某点距离小于多少
这就是个裸的点分树啊
复杂度 O(nlog3n)

#include
#include
#include
#include
using namespace std;

inline char nc(){
  static char buf[100000],*p1=buf,*p2=buf;
  return p1==p2&&(p2=(p1=buf)+fread(buf,1,100000,stdin),p1==p2)?EOF:*p1++;
}
inline void read(int &x){
  char c=nc(),b=1;
  for (;!(c>='0' && c<='9');c=nc()) if (c=='-') b=-1;
  for (x=0;c>='0' && c<='9';x=x*10+c-'0',c=nc()); x*=b;
}

const int N=100005;

struct edge{
  int u,v,w,next;
}G[N<<1];
int head[N],inum;
inline void add(int u,int v,int w,int p){
  G[p].u=u; G[p].v=v; G[p].w=w; G[p].next=head[u]; head[u]=p;
}
#define V G[p].v

int fat[N][25],dis[N][25];

int del[N];

int size[N],sum,minv,rt;
inline void Root(int u,int fa){
  size[u]=1; int maxv=0;
  for (int p=head[u];p;p=G[p].next)
    if (V!=fa && !del[V])
      Root(V,u),size[u]+=size[V],maxv=max(maxv,size[V]);
  maxv=max(maxv,sum-size[u]);
  if (maxvint cur,cnt;
inline void dfs(int u,int fa,int d){
  fat[u][++*fat[u]]=cur; dis[u][++*dis[u]]=d; ++cnt;
  for (int p=head[u];p;p=G[p].next)
    if (V!=fa && !del[V])
      dfs(V,u,d+G[p].w);
}

inline void Divide(int u){
  del[u]=1; cur=u;
  fat[u][++*fat[u]]=u; dis[u][++*dis[u]]=0;
  for (int p=head[u];p;p=G[p].next)
    if (!del[V]){
      cnt=0;
      dfs(V,u,G[p].w);
      size[V]=cnt;
    }
  for (int p=head[u];p;p=G[p].next)
    if (!del[V]){
      sum=size[V],minv=1<<30,Root(V,0);
      Divide(rt);
    }
}
#define pb push_back 
vector<int> T[N],F[N];

inline int Bin(vector<int> &A,int B){
  return upper_bound(A.begin(),A.end(),B)-A.begin();
}

inline int count(int x,int d){
  int ret=0;
  for (int j=1;j<=*fat[x];j++){
    ret+=Bin(T[fat[x][j]],d-dis[x][j]);
    if (j!=1) ret-=Bin(F[fat[x][j-1]],d-dis[x][j]);
  }
  return ret;
}

int n,K;

inline int Solve(int x){
  int L=0,R=1<<30,MID;
  while (L+1if (count(x,MID=(L+R)>>1)else
      R=MID;
  printf("%d\n",R);
}

int main(){
  int iu,iv,iw;
  freopen("t.in","r",stdin);
  freopen("t.out","w",stdout);
  read(n); read(K); K++;
  for (int i=1;i1<<30,Root(1,0);
  Divide(rt);
  for (int i=1;i<=n;i++){
    reverse(fat[i]+1,fat[i]+*fat[i]+1),reverse(dis[i]+1,dis[i]+*dis[i]+1);
    for (int j=1;j<=*fat[i];j++){
      T[fat[i][j]].pb(dis[i][j]);
      if (j!=1)
    F[fat[i][j-1]].pb(dis[i][j]);
    }
  }
  for (int i=1;i<=n;i++) sort(T[i].begin(),T[i].end()),sort(F[i].begin(),F[i].end());
  // printf("%d\n",T[1].size());
  for (int i=1;i<=n;i++)
    Solve(i);
  return 0;
}