洛谷.2325.[SCOI2005]王室联邦(贪心)

#include <cstdio>
#include <cctype>
#define gc() getchar()
const int N=1005;

int n,B,Enum,H[N],to[N<<1],nxt[N<<1],sk[N],num,bel[N],cnt,capt[N];

inline int read()
{
    int now=0;register char c=gc();
    for(;!isdigit(c);c=gc());
    for(;isdigit(c);now=now*10+c-'0',c=gc());
    return now;
}
inline void AddEdge(int u,int v){
    to[++Enum]=v, nxt[Enum]=H[u], H[u]=Enum;
    to[++Enum]=u, nxt[Enum]=H[v], H[v]=Enum;
}
void DFS(int x,int f)
{
    int cur=num;
    for(int i=H[x]; i; i=nxt[i])
        if(to[i]!=f)
        {
            DFS(to[i],x);
            if(num>=B+cur)
            {
                capt[++cnt]=x;
                while(num>cur)
                    bel[sk[num--]]=cnt;
            }
        }
    sk[++num]=x;
}

int main()
{
    n=read(),B=read();
    for(int u,v,i=1; i<n; ++i) u=read(),v=read(),AddEdge(u,v);
    if(n<B) {putchar('0'); return 0;}
    DFS(1,1);
    while(num) bel[sk[num--]]=cnt;
    printf("%d\n",cnt);
    for(int i=1; i<n; ++i) printf("%d ",bel[i]);
    printf("%d\n",bel[n]);
    for(int i=1; i<=cnt; ++i) printf("%d ",capt[i]);

    return 0;
}