题解:n个气球 从1到n染色,如果a、b和c是不同的正方形,a和b在它们之间有一条直接的路径,b和c之间有一条直接的路径,然后在这三个方块上的气球颜色是不同的。

AC代码

#include <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include <iostream>
#include <sstream>
#include <algorithm>
#include <string>
#include <queue>
#include <vector>
using namespace std;
const int maxn= ;
const int inf = 0x3f3f3f3f;
typedef long long ll;
int color[maxn];
std::vector<int> v[maxn];
int n,ans=;
void dfs(int now,int father)
{
int i,k;
k=;
for(i=; i<v[now].size(); i++)
{
if(color[v[now][i]]!=inf)
{
continue; //该点已经访问过,直接下一个邻接点
}
k++;
while(color[now]==k||color[father]==k) //确定颜色
{
k++;
}
color[v[now][i]]=k;
dfs(v[now][i],now);
}
ans=ans<k?k:ans;
}
int main(int argc, char const *argv[])
{
int a,b;
cin>>n;
for(int i=; i<n-; i++)
{
cin>>a>>b;
v[a].push_back(b); //存图的边
v[b].push_back(a);
}
memset(color,inf,sizeof(color));
color[]=;
color[]=;
dfs(,);
cout<<ans<<endl;
for(int i=; i<n; i++)
{
cout<<color[i]<<" ";
}
cout<<color[n]<<endl;
return ;
}
C. Andryusha and Colored Balloons
time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

Andryusha goes through a park each day. The squares and paths between them look boring to Andryusha, so he decided to decorate them.

The park consists of n squares connected with (n - 1) bidirectional paths in such a way that any square is reachable from any other using these paths. Andryusha decided to hang a colored balloon at each of the squares. The baloons' colors are described by positive integers, starting from 1. In order to make the park varicolored, Andryusha wants to choose the colors in a special way. More precisely, he wants to use such colors that if ab and c are distinct squares that a and b have a direct path between them, and b and c have a direct path between them, then balloon colors on these three squares are distinct.

Andryusha wants to use as little different colors as possible. Help him to choose the colors!

Input

The first line contains single integer n (3 ≤ n ≤ 2·105) — the number of squares in the park.

Each of the next (n - 1) lines contains two integers x and y (1 ≤ x, y ≤ n) — the indices of two squares directly connected by a path.

It is guaranteed that any square is reachable from any other using the paths.

Output

In the first line print single integer k — the minimum number of colors Andryusha has to use.

In the second line print n integers, the i-th of them should be equal to the balloon color on the i-th square. Each of these numbers should be within range from 1 to k.

Examples
input
3
2 3
1 3
output
3
1 3 2
input
5
2 3
5 3
4 3
1 3
output
5
1 3 2 5 4
input
5
2 1
3 2
4 3
5 4
output
3
1 2 3 1 2
Note

In the first sample the park consists of three squares: 1 → 3 → 2. Thus, the balloon colors have to be distinct.

Illustration for the first sample.

In the second example there are following triples of consequently connected squares:

  • 1 → 3 → 2
  • 1 → 3 → 4
  • 1 → 3 → 5
  • 2 → 3 → 4
  • 2 → 3 → 5
  • 4 → 3 → 5

We can see that each pair of squares is encountered in some triple, so all colors have to be distinct.Illustration for the second sample.

In the third example there are following triples:

  • 1 → 2 → 3
  • 2 → 3 → 4
  • 3 → 4 → 5

We can see that one or two colors is not enough, but there is an answer that uses three colors only.Illustration for the third sample.

Codeforces780C的更多相关文章

随机推荐

  1. 个人的MySql配置总结

    lower_case_table_names参数是用来设置MySQL是否让Schema和数据表大小写敏感,我测试的是在查询界面和MySQL控制台界面无法改变它的值,要在配置文件中改变(先关闭服务),一 ...

  2. 探索C++对象模型

    只说C++对象模型在内存中如何分配这是不现实的,所以这里选择VS 2013作为调试环境具体探讨object在内存中分配情况.目录给出了具体要探讨的所有模型,正文分标题依次讨论.水平有限,如有错误之处请 ...

  3. Java I/O---RandomAccessFile类(随机访问文件的读取和写入)

    1.JDK API中RandomAccessFile类的描述 此类的实例支持对随机访问文件的读取和写入.随机访问文件的行为类似存储在文件系统中的一个大型 byte 数组.存在指向该隐含数组的光标或索引 ...

  4. geoserver集成以及部署arcgis server瓦片数据

    关注重点: 一般来说,geoserver是不支持arcgis server格式瓦片数据部署的,至少我本机的geoserver版本(2.8.5)以及之前的版本并没有集成进来,不知道目前官网的最新版是否支 ...

  5. ArcGIS 网络分析[2] 在ArcMap中使用网络数据集进行五大网络分析[最短路径/服务区/最近设施点/OD成本矩阵/车辆分配]

    上一章花了大篇幅介绍网络数据集的创建,也简单说了下点线的连通性问题. 那么可以试试刀锋不锋利啦! 网络分析呢,ArcGIS提供了5个基本分析类型: 最短路径求解 服务区(服务覆盖范围) 事故突发地的最 ...

  6. bzoj 2752: [HAOI2012]高速公路(road)

    Description Y901高速公路是一条重要的交通纽带,政府部门建设初期的投入以及使用期间的养护费用都不低,因此政府在这条高速公路上设立了许多收费站.Y901高速公路是一条由N-1段路以及N个收 ...

  7. vue2 vue-rout

    vue 2.0的路由比起1.0简单了许多,分为以下几个步骤: 1.创建路由块和视图块: to里面是要切换的路径名称 <div id="app"> <div> ...

  8. lesson - 9 课程笔记

    一. yum          作用:                     yum 命令是在Fedora 和RedHat 以及SUSE 中基于rpm 的软件包管理器,它可以使系统管理人员交互和自动 ...

  9. Generation Axe 吉他之夜音乐会-广州站 感受

    本人第一次看音乐会,演唱会跟音乐会是有区别的哈,演唱会以表演.舞蹈.歌唱为主,还有很多特别嘉宾 演出时间: 从20点开始一直到23点多才结束,有五个吉他手,开场跟结束五个吉他手一齐演出.平均每个人表演 ...

  10. (转)top关键字与top表达式(SQLServer)

    SQLServer 中,top也很有用,例如查询部分数据,还可以用表达式.其语法如下: SELECT TOP number|percent column_name(s) FROM table_name ...