[091212] TJUOJ 1077 - Channel Allocation
Post date: Sep 13, 2012 5:46:27 AM
http://acm.tju.edu.cn/toj/showp1077.html
As a follow up to our discussions today, I have an example where the BFS method - where you assign colors to vertices greedily following a BFS order - fails.
6
A:BC
B:AF
C:ADE
D:CEF
E:CDF
F:BDE
Here is a graphical representation of it:
If we start by assigning the value 1 to A, then you will end up with this assignment.
However, the optimal coloring is:
Re: Paul, doing this in order of degree wouldn't help at all, because we can make any vertex have an arbitrary degree.