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 a, b 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.

题意:

给你一个图,给所有节点染上颜色,要求是相邻的三个节点的颜色不能相同,求需要的最少的颜色数

思路:

为了方便叙述,我们给颜色编号,从1开始,不一样的序号代表不一样的颜色,序号最大者即为需要的颜色种数

首先,由题目上的条件,这个图一定是一棵树,因为是一颗树,我们可以从任一节点开始,DFS遍历完所有节点。

结合图为树的条件,经过分析得到,要使每相邻三个节点的颜色不同,

只需满足两个条件:

1.使这个节点和他的兄弟节点颜色不同

2.使这个节点和它的的父亲节点及爷爷节点颜色不同

为了满足这两个条件,并使得颜色数最少,我们在DFS到一个节点时,遍历他所有的子节点,都染上颜色,颜色序号在满足以上条件时要尽可能的小

Codeforces Round #403---C题(DFS,树)的更多相关文章

  1. Codeforces Round #403 (Div. 2, based on Technocup 2017 Finals)

    Codeforces Round #403 (Div. 2, based on Technocup 2017 Finals) 说一点东西: 昨天晚上$9:05$开始太不好了,我在学校学校$9:40$放 ...

  2. 树的性质和dfs的性质 Codeforces Round #403 (Div. 2, based on Technocup 2017 Finals) E

    http://codeforces.com/contest/782/problem/E 题目大意: 有n个节点,m条边,k个人,k个人中每个人都可以从任意起点开始走(2*n)/k步,且这个步数是向上取 ...

  3. Codeforces Round #403 (Div. 2, based on Technocup 2017 Finals)A模拟 B三分 C dfs D map

    A. Andryusha and Socks time limit per test 2 seconds memory limit per test 256 megabytes input stand ...

  4. Codeforces Round #403 (Div. 2) B 三分 C dfs

    B. The Meeting Place Cannot Be Changed time limit per test 5 seconds memory limit per test 256 megab ...

  5. 【贪心】【DFS】Codeforces Round #403 (Div. 2, based on Technocup 2017 Finals) C. Andryusha and Colored Balloons

    从任意点出发,贪心染色即可. #include<cstdio> #include<algorithm> using namespace std; int v[200010< ...

  6. Codeforces 842C--Ilya And The Tree(dfs+树)

    原题链接:http://codeforces.com/contest/842/problem/C 题意:一个以1为根节点的树,每个节点有一个值ai,定义美丽度:从根节点到这个节点的路径上所有ai的gc ...

  7. Codeforces Round #403 (Div. 1, based on Technocup 2017 Finals)

    Div1单场我从来就没上过分,这场又剧毒,半天才打出B,C挂了好几次最后还FST了,回紫了. AC:AB Rank:340 Rating:2204-71->2133 Div2.B.The Mee ...

  8. Codeforces Round#403 (Div. 1)

    唉,昨天晚上迷迷糊糊地去打cf,结果fst两题,掉回蓝了... A.Andryusha and Colored Balloons 题意:给定一棵树,任意两个距离小等于二的点不能染相同的颜色,求最小颜色 ...

  9. Codeforces Round #456 B题

    一.题意 给你一个n和一个k,让你从[1, n]区间内选k个数,这k个数异或和最大. 二.思路 我一开始看到这种题,不自觉地就想到,莫非又要搞很复杂的线段树.主席树?貌似还有些难搞啊.然而事实是:Co ...

  10. 2-sat Codeforces Round #403 (Div. 2, based on Technocup 2017 Finals) D

    http://codeforces.com/contest/782/problem/D 题意: 每个队有两种队名,问有没有满足以下两个条件的命名方法: ①任意两个队的名字不相同. ②若某个队 A 选用 ...

随机推荐

  1. 配置Bean的作用域

    一.Spring中Bean的5个作用域 在Spring 2.0及之后的版本中,Bean的作用域被划分为5种.如下 singleton  默认值.以单例模式创建Bean的实例,即容器中该Bean的实例只 ...

  2. HDU-4219-Randomization?

    题目描述 给定一棵\(n\)个节点的树,每条边的权值为\([0,L]\)之间的随机整数,求这棵树两点之间最长距离不超过\(S\)的概率. Input 第一行三个整数\(n,L,S\) 接下来n-1行, ...

  3. Maven build 命令介绍(转)

    常用命令: 打包:mvn package编译:mvn compile清空:mvn clean(清除编译后目录,默认是target目录)运行测试:mvn test安装jar包到本地仓库中:mvn ins ...

  4. Codeforces 1209E2. Rotate Columns (hard version)

    传送门 发现 $n$ 很小,考虑状压 $dp$,但是如果强行枚举列并枚举置换再转移复杂度太高了 考虑推推结论,发现我们只要保留列最大值最大的 $n$ 列即可,证明好像挺显然: 假设我们让列最大值比较小 ...

  5. Python 经典面试题(一)

    一.浮点数运算 题目 判断浮点数的运行结果是否相等:  a = 0.1 b = 0.2 c = 0.3 assert a + b == c 题目解析: 本题考查的是计算机的浮点运算知识点.不仅是 py ...

  6. Let和Const的使用

    ES2015(ES6) 新增加了两个重要的 JavaScript 关键字: let 和 const. let 声明的变量只在 let 命令所在的代码块内有效,const 声明一个只读的常量,一旦声明, ...

  7. 生成二维码(java后端)

    需要引入2个jar包: <dependency> <groupId>com.google.zxing</groupId> <artifactId>jav ...

  8. Vue的双向数据绑定的原理

    Vue数据双向绑定的原理就是采用数据劫持结合发布者-订阅者模式,通过object.defineProperty()来劫持各个属性的setter,getter,在数据变动时发布消息给订阅者,触发相应的监 ...

  9. 八、break和continue

  10. vue-cli3.0中使用 postcss-pxtorem

    vue.config.js module.exports = { lintOnSave: true, css: { loaderOptions: { postcss: { plugins: [ req ...