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Re: e

by I0 (Priest)
on Jul 17, 2004 at 06:04 UTC ( #375201=note: print w/replies, xml ) Need Help??

in reply to e

sub e{ use integer; my @e=(1) x shift; for(1..@e*log(@e)/3){ for(reverse(1..$#e)){ $e[$_-1]+=$e[$_]/$_; $e[$_]%=$_; } printf"%01d",$e[0]; $e[0]=0; $_*=10 for @e; } }

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Re^2: e
by tachyon (Chancellor) on Jul 17, 2004 at 07:28 UTC

    Cool. Lovely piece of code.

    Map gets it down to 105 chars - yes void maps are good for golf only!

    sub e{ #234567890123456789012345678901234567890123456789012 @e=(1)x pop;map{map{$e[$_-1]+=$e[$_]/$_;$e[$_]=10*($ e[$_]%$_)}reverse 1..$#e;print int$e[0];$e[0]=0}1..@e } # or if you prefer whitespace and no void maps sub e{ @e=(1)x pop; for(1..@e){ for(reverse(1..$#e)){ $e[$_-1]+=$e[$_]/$_; $e[$_]=10*($e[$_]%$_) } print int $e[0]; $e[0]=0 } }



    Re^3: e
    by mtve (Deacon) on Jul 17, 2004 at 09:36 UTC

      Simple optimizations down to 86:

      sub e{ #234567890123456789012345678901234567890123456789012 map{$e[$q-1]+=$e[$q]/$q,($e[$q]%=$q--).=0for 1..($q=@e);$e[0]=!print"@e"|0}@e=(1)x pop } e(1000);

      Update from tybalt89 - 80 chars:

      $=[!print$=]=!map{$==$=[$#z]+=$=[@z]/@z,($=[@z]%=1+$#z--).=0}@z=@=for@ +==(1)x pop
      Re^4: e
      by shmem (Chancellor) on Sep 13, 2015 at 09:47 UTC
        $=[!print$=]=!map{$==$=[$#z]+=$=[@z]/@z,($=[@z]%=1+$#z--).=0}@z=@=for@ +==(1)x pop

        Segfaults with perl v5.18.2:

        qwurx [shmem] ~> perl -e '$=[!print$=]=!map{$==$=[$#z]+=$=[@z]/@z,($=[ +@z]%=1+$#z--).=0}@z=@=for@==(1)x pop' 10 Attempt to free unreferenced scalar: SV 0xdd0968, Perl interpreter: 0x +da4010 at -e line 1. Segmentation fault

        Works with v5.10.1 though. Looks like the segfault happens here:


        Can't (for now) figure out why.

        perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'

        There was a bug in the code I posted. AFAIK it does not effect the result per se just the efficiency. By trying to scrape a char by using @e instead of $#e (as used in IOs code) within the inner loop we are accessing a non existent element one past the end of the array. As a result @e is growing by one with each inner loop.



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