BZOJ 1086 王室联邦

orz POPOQQQ。。。好评！

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define maxv 1050
#define maxe 2050
using namespace std;
int n,b,x,y,g[maxv],nume=0,stack[maxv],top=0,root[maxv],cnt=0,bel[maxv];
struct edge
{
    int v,nxt;
}e[maxe];
void addedge(int u,int v)
{
    e[++nume].v=v;
    e[nume].nxt=g[u];
    g[u]=nume;
}
void dfs(int x,int fath)
{
    int bottom=top;
    for (int i=g[x];i;i=e[i].nxt)
    {
        int v=e[i].v;
        if (v==fath) continue;
        dfs(v,x);
        if (top-bottom>=b)
        {
            root[++cnt]=x;
            while (top!=bottom) bel[stack[top--]]=cnt;
        }
    }
    stack[++top]=x;
}
int main()
{
    scanf("%d%d",&n,&b);
    for (int i=1;i<=n-1;i++)
    {
        scanf("%d%d",&x,&y);
        addedge(x,y);addedge(y,x);
    }
    dfs(1,0);
    while (top) bel[stack[top--]]=cnt;
    printf("%d
",cnt);
    for (int i=1;i<=n;i++) printf("%d ",bel[i]);printf("
");
    for (int i=1;i<=cnt;i++) printf("%d ",root[i]);printf("
");
    return 0;
}