标签：uva   acm   graph   dfs   

题目如下：

Bicoloring

Here you are asked to solve a simpler similar problem. Youhave to decide whether a given arbitrary connected graph can be bicolored.That is, if one can assign colors (from a palette of two) to the nodes in sucha way that no two adjacent nodes have the same color. To simplify the problemyou can assume:

• no node will have an edge to itself.
• the graph is nondirected. That is, if a node a is said to be connectedto a node b, then you must assume that b is connected to a.
• the graph will be strongly connected. That is, there will be at leastone path from any node to any other node.

Input 

An input with n = 0 will mark the end of the input and isnot to be processed.

Output 

Sample Input 

3
3
0 1
1 2
2 0
9
8
0 1
0 2
0 3
0 4
0 5
0 6
0 7
0 8
0

Sample Output 

NOT BICOLORABLE.
BICOLORABLE.

问是否可以用两种颜色将一个无向强联通图染色，其实可以转化为这个图是否是二分图。二分图的充要条件是图中的每个圈都是偶数，所以用DFS找出图中每个圈的长度，再判断是否是偶数，值得注意的是vis标记数组不应该标记节点，因为节点可能访问多次，而应该为二维数组标记边，在找圈过程中边是不能重复遍历的，1A。

AC的代码如下：

UVA 10004 Bicoloring,布布扣,bubuko.com

UVA 10004 Bicoloring

标签：uva   acm   graph   dfs   

原文地址：http://blog.csdn.net/u013840081/article/details/36885971