Calculating the sum of a *lot* of primes

[Geoff Canyon]

...and I just accidentally clicked the button a second time and overwrote
the file, so I have to let it run a few hours again to generate the primes
again. :-/

On Thu, Nov 12, 2015 at 1:26 AM, Geoff Canyon <gcanyon at gmail.com> wrote:

> I re-wrote the algorithm a bit to tweak for speed, then ran it
> successfully for primes up to 3 billion (a couple hours), and got the wrong
> answer because my big addition function was broken :-/
>
> So I broke the problem in two: first generate the list of primes, then do
> the addition.
>
> For the primes I generated the list up to 100,000, stored that, and then
> used a simpler (by one command) routine to generate the primes to 10
> billion in a few hours. Here's that:
>
> on mouseUp
>    put the long seconds into ST
>    repeat for each line i in line 2 to -1 of the primeList of this stack
>       put 2*i & comma after P[i^2]
>    end repeat
>    put 2 into pList
>    put fld "path" into fPath
>    open file fPath for write
>    put 0 into S
>    put fld 1 into endPoint
>    if endPoint mod 2 = 0 then subtract 1 from endPoint
>    repeat with i = 3 to endPoint step 2
>       if P[i] is empty then
>          put cr & i after pList
>       else
>          repeat for each item x in P[i]
>             put x & comma after P[i + x]
>          end repeat
>       end if
>       if the seconds > S then
>          put the seconds + 5 into S
>          put i into fld 2
>          write pList to file fPath
>          put empty into pList
>          unlock screen
>          lock screen
>       end if
>       delete variable P[i]
>    end repeat
>    put i into fld 2
>    write pList to file fPath
>    close file fPath
>    put the long seconds - ST
> end mouseUp
>
> That's ~5gb of primes...
>
> Then I re-wrote the addition function to use a simpler, slower method,
> tested it, and let it go. An hour or so later, and I had my answer
> (validated against the site with the challenge). If anyone sees the problem
> with bAdd, I'm all ears. I didn't look too closely, since I just wanted to
> get the code running to solve the problem. It works for all the test cases
> I tried, but it seems to fail on the boundary between 14 and 15 digit
> numbers.
>
>
> on mouseUp
>    put fld "path" into fPath
>    open file fPath for read
>    put 0 into T
>    put 0 into S
>    repeat with C = 1 to 999999999999
>       read from file fPath for 1 line
>       if it > fld 1 then exit repeat
>       put bAdd2(T,char 1 to -2 of it) into T
>       if the seconds > S then
>          put the seconds + 1 into S
>          put T && it && C into fld 2
>          unlock screen
>          lock screen
>       end if
>    end repeat
>    put T && it && C - 1 into fld 2
>    close file fPath
> end mouseUp
>
> function bAdd x,y
>    put 0 into c
>    repeat with i = 14 to max(length(x),length(y)) step 14
>       add char -i to 13 - i of x + char -i to 13 - i of y to c
>       put char -14 to -1 of c before r
>       delete char -14 to -1 of c
>    end repeat
>    return c & r
> end bAdd
>
> function bAdd2 x,y
>    put 0 into c
>    repeat with i = 1 to max(length(x),length(y))
>       put char -i of x + char -i of y + c into c
>       put char -1 of c before r
>       delete char -1 of c
>    end repeat
>    return c & r
> end bAdd2
>