From: Link on
Theorem: The maximum cut problem can be


approximated in polynomial time within 1.14*OPT.


=1.0625*OPT
From: marty.musatov on
> Theorem: The maximum cut problem can be
>
>
> approximated in polynomial time within 1.14*OPT.
>
>
> =1.0625*OPT

One of Karp's original NP-complete problems.


A


B


C


D


E


A


B


C


D


E


Input graph


Heuristic solution


Optimal solution


A


B


C


D


E


cut size = 2


cut size = 4


cut size = 5


Maximum Cut


Theorem [Karp, 1972]: The minimum vertex cover


problem is NP-complete.


Theorem: The maximum cut problem can be solved


in polynomial time for planar graphs.


Theorem: The maximum cut problem can not


be approximated within £ 17/16*OPT unless P=NP.


Theorem: The maximum cut problem can be


approximated in polynomial time within 2*OPT.


Theorem: The maximum cut problem can be


approximated in polynomial time within 1.14*OPT.


=1.0625*OPT


Maximum Cut


Algorithm: 2*OPT approximation for maximum cut:


Start with an arbitrary node partition


If moving an arbitrary node across the partition
will improve the cut, then do so


Repeat until no further improvement is possible


Idea: final cut must contain at least half of all edges.


Þ Heuristic solution is no worse than 2*OPT.


A


B


C


D


E


Input graph


Heuristic solution


Optimal solution


cut size = 2


cut size = 3


A


B


C


D


E


A


B


C


D


E


cut size = 5