Hey guys,

the general issue of this topic are NP problems.
http://en.wikipedia.org/wiki/NP-complete

I got a few questions,

- how do I show that a problem is in the P class?
my thoughts:
If I can create an Algororithm that solves the Problem in Polynomial Time --> in P

- how do I show that a problem is in the NP class?
my thoughts:
If I can guess a solution and show that I can verify it in Polynomial Time --> in NP

- how can I prove that something is NP complete?
my thoughts:
I have to show that the Problem is in NP
I have to show that the Problem is NP-hard
I can reduce a given NP-Problem to my current Problem to prove it by Reduction

In general I know:

P is subset of NP
NP-Complete is Subset of NP
NP-Complete is Subset of NP-hard

I just lack the knowledge to Prove such things properly.
i need some advices to get a way in general.

thx in Advance!