Can the Subset Sum Problem Be Solved in Polynomial Time?

  • Thread starter Thread starter RagingHadron
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the Subset Sum Problem, specifically whether it can be solved in polynomial time. Participants explore the implications of the problem in relation to the P vs NP question, and they examine a specific example involving a set of integers.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant presents a mathematical expression attempting to relate exponential time complexity to polynomial time complexity in the context of the Subset Sum Problem.
  • Another participant points out a misunderstanding regarding the formulation of the problem, emphasizing the need for clarity in stating whether a non-empty subset sums to zero.
  • There is a request for clarification on the specific Wikipedia article being referenced, indicating potential confusion about the source material.
  • A participant acknowledges a flaw in their earlier reasoning after further reflection.

Areas of Agreement / Disagreement

Participants express differing levels of understanding regarding the problem and its implications, with some clarifying points of confusion while others remain uncertain about the correctness of the mathematical approach presented.

Contextual Notes

There are unresolved assumptions regarding the definitions and implications of the Subset Sum Problem, as well as the mathematical expressions proposed by participants. The discussion does not reach a consensus on the validity of the approaches discussed.

RagingHadron
Messages
18
Reaction score
0
So I really know very little about the subject but from the little I could gather online...
Consider the subset problem on wikipedia. Does a subset of {−2, −3, 15, 14, 7, −10} equal zero? It shows the work for you and then says that no algorithm to find it in polynomial time is known, only in exponential (with (2^n)-1 tries) It says that an algorithm can only exist in polynomial time if P=NP. So now, can we not set (2^n)-1=n^x so that the algorithm in polynomial time is n^((log((2^n)-1)+2i∏c)/(log(n)) where c∈Z, Z being the set of integers. Does that make any sense?
 
Technology news on Phys.org
RagingHadron said:
So I really know very little about the subject but from the little I could gather online...
Consider the subset problem on wikipedia.
http://en.wikipedia.org/wiki/Subset-sum_problem
RagingHadron said:
Does a subset of {−2, −3, 15, 14, 7, −10} equal zero?
As you have written this, it doesn't make sense. Each subset of some other set is itself a set, and a set is not equal to a number. The actual description is "is there a non-empty subset whose sum is zero?"
RagingHadron said:
It shows the work for you and then says that no algorithm to find it in polynomial time is known, only in exponential (with (2^n)-1 tries) It says that an algorithm can only exist in polynomial time if P=NP. So now, can we not set (2^n)-1=n^x so that the algorithm in polynomial time is n^((log((2^n)-1)+2i∏c)/(log(n)) where c∈Z, Z being the set of integers. Does that make any sense?
 
Mark44 said:
The actual description is "is there a non-empty subset whose sum is zero?"

Yeah that's what I meant. But what was wrong with the rest of it?
 
Which wikipedia article were you reading? I provided a link to the one I thought you were referring to, but I don't see in that one some of what you're talking about.
 
It was in the p versus np problem page specifically, http://en.m.wikipedia.org/wiki/P_versus_NP_problem here. It's in the third paragraph. But was the work that I did correct/incorrect? I'm sure that there's a flaw in my approach to the problem somewhere seeing as it's so simple...
 
Never mind, I saw what my flaw was.
 

Similar threads

  • · Replies 17 ·
Replies
17
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
9
Views
3K
  • · Replies 13 ·
Replies
13
Views
4K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 11 ·
Replies
11
Views
5K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 17 ·
Replies
17
Views
2K