ranse

#include<cstdio>

#include<cstring>

#include<algorithm>

#define maxn 100000000

int son[maxn],hson[maxn],top[maxn],deep[maxn],id[maxn],tree[maxn];

int to[maxn],next[maxn],pre[maxn];

int color[maxn],soncolor[maxn];

int n,m,M;

inline int RD()

{

char ch;

int res=0;

ch=getchar();

while(ch<‘0‘||ch>‘9‘)ch=getchar();

res=ch-‘0‘;

while((ch=getchar())>=‘0‘&&ch<=‘9‘)res=res*10+ch-‘0‘;

return res;

}

void addedge(int a,int b)

{

static int tip=0;

next[++tip]=pre[a],pre[a]=tip,to[tip]=b;

next[++tip]=pre[b],pre[b]=tip,to[tip]=a;

}

void dfs1(int father,int now)

{

deep[now]=deep[father]+1;

for(int i=pre[now];i;i=next[now])

{

if(to[i]!=father)

{

dfs1(now,to[i]);

son[now]+=son[to[i]];

if(son[to[i]]>son[hson[now]])hson[now]=to[i];

}

}

if(!son[now])son[now]=1;

}

void dfs2(int father,int now)

{

static int ID=0;

id[now]=++ID;

if(hson[now])dfs2(now,hson[now])

}

int main()

{

n=RD(),m=RD();

for(int i=1;i<=n;i++)color[i];

for(int i=1;i<n;i++)addedge(RD(),RD());

for(M=1;M<n;M>>1);

dfs1(1,1);dfs2(1,1);

}