今次的 Paper 嘗試証明 SUBSET-SUM Problem 係冇 Polynomial Time, 從而証明 P =/= NP
http://arxiv.org/PS_cache/cs/pdf/0607/0607093v2.pdf
問: 証明那裏出錯了?
(呢份 Paper 只有兩頁... 比佢証明到, 唔單止數學界, 電腦界都要摺埋...)
參考:
http://en.wikipedia.org/wiki/Subset_sum_problem
It is known that every pair of subsets must be compared. For example, take S = {1,2,4,8,16,... 2^n} Then each subsets will give you a different sum. So looking into all subsets is necessary.
What I am thinking is his arguments on "imaginery processor", on the point about the running time to create such processors.
Another note: Because the algorithm required is deterministic, the running time should not depends on the input b. That is, may be for some b, you can prune away a large number of subsets, it is possible that for some other b, you cannot throw away anything at all.
Take my example above: since each subsets has different sum, reduction for one b probably cannot work for other b
That is my point: the running time should be independent of b. So if I take the b large enough, you can't prune anything, and your running time will be slow.