Talk:Sum and product puzzle: Difference between revisions
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Thundergnat moved page Talk:Sum and Product Puzzle to Talk:Sum and product puzzle: Follow normal task title capitalization policy
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val step3 = step2 filter { prodEq(_).intersect(step2).size == 1 }
: step2 filters the step0 integer pairs for pairs where "For every possible sum decomposition of the number X+Y, the product has in turn more than one product decomposition"
: step3 filters the set defined by step2 for pairs where "The number X*Y has only one product decomposition for which fact 1 is true"
: Perhaps the Haskell or JavaScript versions might seem more legible ? [[User:Hout|Hout]] ([[User talk:Hout|talk]]) 17:35, 21 October 2016 (UTC)
:: Still not explicit enough :-( Sorry Meanwhile I added 2 translations where I could understand the source (AWK and GO/ --[[User:Walterpachl|Walterpachl]] ([[User talk:Walterpachl|talk]]) 18:54, 26 October 2016 (UTC)
::: Do higher order functions feature in the architecture or traditions of REXX ? If not, the patterns of functional composition used in the Haskell and Scala etc examples may be a little hard to translate all that directly. [[User:Hout|Hout]] ([[User talk:Hout|talk]]) 19:18, 3 November 2016 (UTC)
== A question on GO ==
I translated GO to Rexx and the "final" piece missing for understanding is this:
Why does this justify the removal of the pair p??
Shouldn't the pair a/b be discarded???
<pre>
for a := 2; a < s/2+s&1; a++ {
b := s - a
if products[a*b] == 1 {
// Excluded because P would have a unique product
continue pairs</pre>
--[[User:Walterpachl|Walterpachl]] ([[User talk:Walterpachl|talk]]) 19:59, 05 November 2016 (UTC)
: I think I found the answer myself:-) If ANY of the decompositions of the given pair's sum had a unique product I couldn't be sure that P does NOT know. So all pairs resulting in the given sum could be eliminated not just the one at hand. (They will be later on or have already been...) --[[User:Walterpachl|Walterpachl]] ([[User talk:Walterpachl|talk]]) 05:59, 10 November 2016 (UTC)
== Java program inconsistent with others ==
It allows the sum to be equal to maximum value. The threshold for a second solution should be X+Y<1866, not 1865.
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