HDU 5016 Mart Master II (tree verbose)

HDU 5016 Mart Master II (tree verbose)

First, the DFS pre-processes the distance between each point and the number of the base station.
Find the center of gravity, find the distance from each point to the center of gravity, and then, according to dis [x] + dis [y] <d [y], use two points to find the number that is not occupied in the current subtree. The total number of points minus the number that is occupied. In this way, we can find the maximum number of vertices occupied by each vertex. Find the maximum value.
The Code is as follows:

#include 
  
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    #include 
    
     #include 
     
      #include #include 
      
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           using namespace std;#define LL __int64#define pi acos(-1.0)#pragma comment(linker, /STACK:1024000000)const int mod=1e9+7;const int INF=0x3f3f3f3f;const double eqs=1e-9;const int MAXN=100000+10;int head[MAXN], cnt, root, min1, tot;int siz[MAXN], vis[MAXN], d[MAXN], id[MAXN], ans[MAXN], dis[MAXN];int color[MAXN];struct node{ int v, w, next;}edge[MAXN<<1];void add(int u, int v, int w){ edge[cnt].v=v; edge[cnt].w=w; edge[cnt].next=head[u]; head[u]=cnt++;}struct N{ int dis, id;}F[MAXN];bool cmp(N x, N y){ return x.dis
           
            d[v]+edge[i].w){ d[u]=d[v]+edge[i].w; id[u]=id[v]; } else if(d[u]==d[v]+edge[i].w) id[u]=min(id[u],id[v]); }}void dfs2(int u, int fa){ for(int i=head[u];i!=-1;i=edge[i].next){ int v=edge[i].v; if(v==fa) continue ; if(d[v]>d[u]+edge[i].w){ d[v]=d[u]+edge[i].w; id[v]=id[u]; } else if(d[v]==d[u]+edge[i].w){ id[v]=min(id[v],id[u]); } dfs2(v,u); }}void getsize(int u, int fa){ siz[u]=1; for(int i=head[u];i!=-1;i=edge[i].next){ int v=edge[i].v; if(v==fa||vis[v]) continue ; getsize(v,u); siz[u]+=siz[v]; }}void getroot(int u, int fa, int s){ int max1=0; for(int i=head[u];i!=-1;i=edge[i].next){ int v=edge[i].v; if(v==fa||vis[v]) continue ; getroot(v,u,s); max1=max(max1,siz[v]); } max1=max(max1,s-siz[u]); if(min1>max1){ min1=max1; root=u; }}void getdis(int u, int fa, int l){ dis[u]=l; F[tot].dis=d[u]-l; F[tot++].id=id[u]; for(int i=head[u];i!=-1;i=edge[i].next){ int v=edge[i].v; if(v==fa||vis[v]) continue ; getdis(v,u,l+edge[i].w); }}int BS(int l, int u){ int low=0, high=tot-1, mid, ans=-1; while(low<=high){ mid=low+high>>1; if(F[mid].dis