# RogerBW's Blog

 The Weekly Challenge 203: Directing the Quadruplets 12 February 2023 I’ve been doing the Weekly Challenges. The latest involved list searching and directory evaluation. (Note that this is open until 12 February 2023.) Task 1: Special Quadruplets You are given an array of integers. Write a script to find out the total special quadruplets for the given array. Special Quadruplets are such that satisfies the following 2 rules. 1) nums[a] + nums[b] + nums[c] == nums[d] 2) a < b < c < d So this is basically the same pattern as challenges 187 part 2 and 188 part 1, similarly without any possibilities of short-cuts to avoid inner loops. Some languages have a readily-accessible combinations generator; others don't. Raku: ``````sub specialquads(@l) { my \$ct = 0; for @l.combinations(4) -> @c { if (@c[0] + @c[1] + @c[2] == @c[3]) { \$ct++; } } return \$ct; } `````` PostScript: ``````/specialquads { 5 dict begin /l exch def 0 0 1 l length 4 sub { /ai exch def ai 1 add 1 l length 3 sub { /bi exch def bi 1 add 1 l length 2 sub { /ci exch def ci 1 add 1 l length 1 sub { /di exch def l ai get l bi get add l ci get add l di get eq { 1 add } if } for } for } for } for end } bind def `````` Task 2: Copy Directory You are given path to two folders, `\$source` and `\$target`. Write a script that recursively copy the directory from `\$source` to `\$target` except any files. In other words, replicate the directory structure. I only felt enthusiasm for this in Perl and Raku: Perl using `File::Find`: ``````sub copydir(\$src, \$dst) { my @ds; my \$l = 1 + length(\$src); find(sub{ if (-d \$_) { push @ds,substr(\$File::Find::name, \$l); } }, \$src); foreach my \$d (@ds) { if (defined \$d && length(\$d) > 0) { mkdir "\$dst/\$d"; } } } `````` and Raku using recursion: ``````sub getdirs(\$src) { my @a; for dir(\$src) -> \$e { if (\$e.d) { @a.push(\$e); @a.append(getdirs(\$e)) } } return @a; } sub copydir(\$src, \$dst) { my \$l = 1 + \$src.chars; for map {\$_.substr(\$l)}, getdirs(\$src) -> \$o { mkdir "\$dst/\$o"; } } `````` Full code on github. Comments on this post are now closed. If you have particular grounds for adding a late comment, comment on a more recent post quoting the URL of this one. Search 10 per page 20 per page 50 per page 100 per page Archive Tags 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s 2010s 3d printing action advent of code aeronautics aikakirja anecdote animation anime army astronomy audio audio tech aviation base commerce battletech beer boardgaming book of the week bookmonth chain of command children chris chronicle church of no redeeming virtues cold war comedy computing contemporary cornish smuggler cosmic encounter coup covid-19 crime cthulhu eternal cycling dead of winter doctor who documentary drama driving drone ecchi economics espionage essen 2015 essen 2016 essen 2017 essen 2018 essen 2019 essen 2022 existential risk falklands war fandom fanfic fantasy feminism film firefly first world war flash point flight simulation food garmin drive gazebo genesys geocaching geodata gin gkp gurps gurps 101 gus harpoon historical history horror hugo 2014 hugo 2015 hugo 2016 hugo 2017 hugo 2018 hugo 2019 hugo 2020 hugo 2022 hugo-nebula reread in brief avoid instrumented life javascript julian simpson julie enfield kickstarter kotlin learn to play leaving earth linux liquor lovecraftiana lua mecha men with beards mpd museum music mystery naval noir non-fiction one for the brow opera parody paul temple perl perl weekly challenge photography podcast politics postscript powers prediction privacy project woolsack pyracantha python quantum rail raku ranting raspberry pi reading reading boardgames social real life restaurant reviews romance rpg a day rpgs ruby rust science fiction scythe second world war security shipwreck simutrans smartphone south atlantic war squaddies stationery steampunk stuarts suburbia superheroes suspense television the resistance the weekly challenge thirsty meeples thriller tin soldier torg toys trailers travel type 26 type 31 type 45 vietnam war war wargaming weather wives and sweethearts writing about writing x-wing young adult Special All book reviews, All film reviews
Produced by aikakirja v0.1