EXTREMAL COMBINATORICS
'Extremal combinatorics' is a field of combinatorics, which is itself a part of mathematics. Extremal combinatorics studies how large or how small a collection of finite objects (numbers, graphs, vectors, sets, etc.) can be, if it has to satisfy certain restrictions.
For example, how many people can we invite to a party where among each three people there are two who know each other and two who don't know each other? An easy Ramsey-type argument shows that at most five persons can attend such a party. Or, suppose we are given a finite set of nonzero integers, and are asked to mark an as large as possible subset of them under the restriction that the sum of any two marked integers cannot be marked. It appears that (independent of what the given integers actually are!) we can always mark at least one-third of them.
★ Stasys Jukna, ''Extremal Combinatorics, With Applications in Computer Science'' (preface). Springer-Verlag, 2001. ISBN 3-540-66313-4.
For example, how many people can we invite to a party where among each three people there are two who know each other and two who don't know each other? An easy Ramsey-type argument shows that at most five persons can attend such a party. Or, suppose we are given a finite set of nonzero integers, and are asked to mark an as large as possible subset of them under the restriction that the sum of any two marked integers cannot be marked. It appears that (independent of what the given integers actually are!) we can always mark at least one-third of them.
| Contents |
| References |
References
★ Stasys Jukna, ''Extremal Combinatorics, With Applications in Computer Science'' (preface). Springer-Verlag, 2001. ISBN 3-540-66313-4.
This article provided by Wikipedia. To edit the contents of this article, click here for original source.
psst.. try this: add to faves

العربية
中国
Français
Deutsch
Ελληνική
हिन्दी
Italiano
日本語
Português
Русский
Español