Re: [Jprogramming] Quora Problem

2018-05-20 Thread Don Guinn
​Couldn't sleep last night so as often, worked on problems. Never saw the actually Quora problem, but as I understand it it wants all unique positive integers that add to 100. So far it looks like people are trying to generate all possible number triples and keeping only those that add to 1e6.

Re: [Jprogramming] Quora Problem

2018-05-20 Thread Roger Hui
There is a mistake in your derivation somewhere, because: Using the code in http://code.jsoftware.com/wiki/Essays/Partitions : t=: part 10 $t 42 7 6$t ┌───┬───┬─┬───┬─┬───┐ │10 │9 1│8 2 │8 1

Re: [Jprogramming] Quora Problem

2018-05-20 Thread Henry Rich
Looking at Don's first paragraph, it seems he is trying to generate triplets of unique numbers rather than unique triplets of numbers.  I haven't looked at the code. Henry Rich On 5/20/2018 10:24 AM, Roger Hui wrote: There is a mistake in your derivation somewhere, because: Using the code in

Re: [Jprogramming] Quora Problem

2018-05-20 Thread Henry Rich
Taking advantage of the fact that thepartitions have only 3 elements. If the first number is i, the second number can be anything from 1 to 99-iand the third number is then uniquely fixed. Since ican run from 1 to 98, the total number of such choices is (-: 98 * 99). But thi

Re: [Jprogramming] Quora Problem

2018-05-20 Thread Skip Cave
I can follow Henry's clever solution. 0 ": 6 %~ (-: 98 * 99) + 3 * -: 98 833 I tried to replicate Roger's partition approach, and ran into memory issues. Roger must have more memory on his machine: pnk 4 : 0"0 n=. 0>.x [ k=. y if. 1>:n<.k do. x: (0 wrote: > Taking advant

Re: [Jprogramming] Quora Problem

2018-05-20 Thread Raul Miller
If you are looking for a way of verifying Henry's and Roger's approaches, perhaps this: A partition of three integers summing to X can be broken down into an integer Y and a partition of two integers Z. We want X=Y+Z and we want both integers in Z to not exceed Y. If we ignore the Y constraint, t

Re: [Jprogramming] Quora Problem

2018-05-20 Thread Skip Cave
Raul, I can follow most of your solution, and it looks right. What is bothering me is that I cut & pasted Roger's solution into my JQt and got a different answer: Roger's post: +/ <.@(%&2)@<: n - 3*i.<.n-3 [ n=: 1e2 833 +/ <.@(%&2)@<: n - 3*i.<.n-3 [ n=: 1e3 8 +/ <.@(%&2)@<: n - 3*i.<.

Re: [Jprogramming] Quora Problem

2018-05-20 Thread S H Makdisi
There seems to be a typo in Roger's solution; +/ <.@(%&2)@<: n - 3*i.<.n-3 [ n=: 1e2 _2207 The last '-' in the line should be division, '%' +/ <.@(%&2)@<: n - 3*i.<.n%3 [ n=: 1e2 883 +/ <.@(%&2)@<: n - 3*i.<.n%3 [ n=: 1e4 833 +/ <.@(%&2)@<: n - 3*i.<.n%3 [ n=: 1e6 833

Re: [Jprogramming] Quora Problem

2018-05-20 Thread Don Guinn
Yes, I had a bug in my previous definition for triplescount. Stupid. Should have checked more before speaking. But As I understand the problem, the numbers in each triple should be unique. Looking at has several triples with duplicate numbers. t #~ 3=#&>t +-+-+-+-+-+-+-

Re: [Jprogramming] Quora Problem

2018-05-20 Thread Raul Miller
Where do you get the requirement that the numbers must be unique? The problem stated here was: "How many distinct triplets have a sum of 1,000,000 (provided all numbers are integers and are positive)?" The quora statement of the issue is slightly different, but substantially the same: "How many

Re: [Jprogramming] Quora Problem

2018-05-20 Thread Don Guinn
Thank you, Raul. I stand corrected. On Sun, May 20, 2018 at 6:27 PM, Raul Miller wrote: > Where do you get the requirement that the numbers must be unique? > > The problem stated here was: > > "How many distinct triplets have a sum of 1,000,000 (provided all numbers > are integers and are positi