Robbie Hatley's Perl solutions to The Weekly Challenge 216

challenge-216/robbie-hatley/blog.txt

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+https://hatley-software.blogspot.com/2023/05/robbie-hatleys-solutions-to-weekly_13.html

challenge-216/robbie-hatley/perl/ch-1.pl

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+#! /bin/perl -CSDA
+
+=pod
+
+------------------------------------------------------------------------------------------------------------------------
+COLOPHON:
+This is a 120-character-wide Unicode UTF-8 Perl-source-code text file with hard Unix line breaks ("\x0A").
+¡Hablo Español! Говорю Русский. Björt skjöldur. ॐ नमो भगवते वासुदेवाय. 看的星星，知道你是爱。麦藁雪、富士川町、山梨県。
+
+------------------------------------------------------------------------------------------------------------------------
+TITLE BLOCK:
+ch-1.pl
+Solutions in Perl for The Weekly Challenge 216-1.
+Written by Robbie Hatley on Sat May 13, 2023.
+
+------------------------------------------------------------------------------------------------------------------------
+PROBLEM DESCRIPTION:
+Task 1: Registration Number
+Submitted by: Mohammad S Anwar
+You are given a list of words and a random registration number.
+Write a script to find all the words in the given list that has every letter in the given registration number.
+
+Example 1:
+Input: @words = ('abc', 'abcd', 'bcd'), $reg = 'AB1 2CD'
+Output: ('abcd')
+The only word that matches every alphabets in the given registration number is 'abcd'.
+
+Example 2:
+Input: @words = ('job', 'james', 'bjorg'), $reg = '007 JB'
+Output: ('job', 'bjorg')
+
+Example 3:
+Input: @words = ('crack', 'road', 'rac'), $reg = 'C7 RA2'
+Output: ('crack', 'rac')
+
+------------------------------------------------------------------------------------------------------------------------
+PROBLEM NOTES:
+This is pretty simple. Just check each word to see if it contains all of the letters from the registration string,
+then output the subset of the original word set which contains those members which contain all registration letters.
+I use a ranged for loop to push "registered" words onto a "@regd_wrds" array.
+
+------------------------------------------------------------------------------------------------------------------------
+IO NOTES:
+Input is via either built-in variables or via @ARGV. If using @ARGV, provide one argument which must be a double-quoted
+array of arrays in proper Perl syntax, with each inner array being a sequence of single-quoted words followed by a
+registration string, like so:
+./ch-1.pl "(['Tom', 'Bob', 'Sue', 'O32 M7T'], ['fig', 'apple', 'peach', 'APE H7C'])"
+
+Output is to STDOUT and will be each word list, followed by the registration string, followed by the list of
+"fully-registered" words (words containing all letters from the registration string).
+
+=cut
+
+# ----------------------------------------------------------------------------------------------------------------------
+# PRELIMINARIES:
+use v5.36;
+use strict;
+use warnings;
+use utf8;
+use Sys::Binmode;
+use Time::HiRes 'time';
+use List::Util  'uniq';
+$"=', ';
+
+# ----------------------------------------------------------------------------------------------------------------------
+# SUBROUTINES:
+sub is_in_list ($item, $list) {
+   for (@$list) {$item eq $_ and return 1;}
+   return 0;
+}
+
+sub is_registered ($wrd, $reg) {
+   my @wrdfc = uniq sort split //, fc $wrd =~ s/\PL//gr;
+   my @regfc = uniq sort split //, fc $reg =~ s/\PL//gr;
+   for (@regfc) {is_in_list($_, \@wrdfc) or return 0;}
+   return 1;
+}
+
+# ----------------------------------------------------------------------------------------------------------------------
+# DEFAULT INPUTS:
+my @arrays =
+(
+   [ 'abc',   'abcd',  'bcd',   'AB1 2CD' ],
+   [ 'job',   'james', 'bjorg', '007 JB'  ],
+   [ 'crack', 'road',  'rac',   'C7 RA2'  ],
+);
+
+# ----------------------------------------------------------------------------------------------------------------------
+# NON-DEFAULT INPUTS:
+if (@ARGV) {@arrays = eval($ARGV[0]);}
+
+# ----------------------------------------------------------------------------------------------------------------------
+# MAIN BODY OF PROGRAM:
+{ # begin main
+   my $t0 = time;
+   for my $aref (@arrays) {
+      my @words = @{$aref};
+      my $reg = pop @words;
+      my @regd_wrds = ();
+      for my $word (@words) {
+         if (is_registered($word, $reg)) {
+            push @regd_wrds, $word;
+         }
+      }
+      say '';
+      say "word list         = (@words)";
+      say "registration code = $reg";
+      say "registered words  = (@regd_wrds)";
+   }
+   my $µs = 1000000 * (time - $t0);
+   printf("\nExecution time was %.3fµs.\n", $µs);
+   exit 0;
+} # end main

challenge-216/robbie-hatley/perl/ch-2.pl

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+#! /bin/perl -CSDA
+
+=pod
+
+------------------------------------------------------------------------------------------------------------------------
+COLOPHON:
+This is a 120-character-wide Unicode UTF-8 Perl-source-code text file with hard Unix line breaks ("\x0A").
+¡Hablo Español! Говорю Русский. Björt skjöldur. ॐ नमो भगवते वासुदेवाय. 看的星星，知道你是爱。麦藁雪、富士川町、山梨県。
+
+------------------------------------------------------------------------------------------------------------------------
+TITLE BLOCK:
+ch-2.pl
+Solutions in Perl for The Weekly Challenge 216-2.
+Written by Robbie Hatley on Sat May 13, 2023.
+
+------------------------------------------------------------------------------------------------------------------------
+PROBLEM DESCRIPTION:
+Task 2: Word Stickers
+Submitted by: Mohammad S Anwar
+You are given a list of word stickers and a target word.
+Write a script to find out how many word stickers is needed to make up the given target word.
+
+Example 1:
+Input: @stickers = ('perl','raku','python'), $word = 'peon'
+Output: 2
+We just need 2 stickers i.e. 'perl' and 'python'.
+'pe' from 'perl' and
+'on' from 'python' to get the target word.
+
+Example 2:
+Input: @stickers = ('love','hate','angry'), $word = 'goat'
+Output: 3
+We need 3 stickers i.e. 'angry', 'love' and 'hate'.
+'g' from 'angry'
+'o' from 'love' and
+'at' from 'hate' to get the target word.
+
+Example 3:
+Input: @stickers = ('come','nation','delta'), $word = 'accommodation'
+Output: 4
+We just need 2 stickers of 'come' and one each of 'nation' & 'delta'.
+'a' from 'delta'
+'ccommo' from 2 stickers 'come'
+'d' from the same sticker 'delta' and
+'ation' from 'nation' to get the target word.
+
+Example 4:
+Input: @stickers = ('come','country','delta'), $word = 'accommodation'
+Output: 0
+as there's no "i" in the inputs.
+
+------------------------------------------------------------------------------------------------------------------------
+PROBLEM NOTES:
+This one is tricky. I can't see an iterative way of doing it, and recursive approaches are usually nightmares. Let me
+see if I can find a CPAN for this.... Ah, there is "Math::Combinatorics". Ok, I'll use that, then get all 1,2,3...n
+combinations of "stickers" and stop when I'm either able to make the word (in which case print n), or I've run out of
+combinations (in which case print 0).
+
+COMPLICATION #1: The examples appear to indicate that any letter in any "sticker" may only be used ONCE, much like
+making a sign using letter decals. My first attempt did not get this right, so I had to change the code to make
+sticker letters "non-reusable".
+
+COMPLICATION #2: Example 4 appears to indicate that we have large (unlimited?) numbers of each kind of sticker
+at our disposal. That's going to be very tricky. Should I write code to determine whether it's even POSSIBLE to make
+a work from a given set of skickers, regardless of having multiple copies of each kind available? That could get quite
+complicated. But a simple (if not efficient) approach is, I'll limit sticker copies to the number of letters in the
+word being made, because we know that if a word has n letters, and we can't make it even though we have n copies of
+each sticker in our set, then we can't make that word using those stickers.
+
+COMPLICATION #3: Oops, while the approach I lay out in #2 above technically works, for a word such as "accomodation",
+with a sticker-type set NOT containing all those letters, it can take HOURS for the program to realized that it simply
+can't be done and print "0". So I had to also create a "cant_make" sub to check for that. Now the run time dropped from
+"several hours" down to about 810µs.
+
+COMPLICATION #4: The approach in #3 above works well enough for words requiring 1, 2, or 3 "multiples" of the original
+set of sticker types, but for more multiples, it can take several seconds. This could be dramatically improved by having
+sub "can_make" report back info on which letters we "ran out of", then have number_of_stickers_needed only duplicate
+the NECESSARY sticker types instead of duplicating ALL sticker types. But I'm not going to Level 4 with this program;
+I spent an entire Saturday afternoon on it as it is. Level 3, while not "optimum", is "good enough" for this exercise.
+
+------------------------------------------------------------------------------------------------------------------------
+IO NOTES:
+Input is via either built-in variables or via @ARGV. If using @ARGV, provide one argument which must be a double-quoted
+array of arrays in proper Perl syntax, with each inner array being a sequence of single-quoted words to be used as
+"stickers" (decals) followed by a word to be made from those stickers, like so:
+./ch-2.pl "(['horse', 'pig ', 'goat', 'port'], ['dog', 'pig', 'cow', 'ddddd'], ['fig', 'apple', 'peach', 'helm'])"
+
+Output is to STDOUT and will be the word to be made, followed by a list of sticker types from which the word is to be
+made, followed by the number of stickers required (or "0" if the word can't be made from those sticker types).
+
+=cut
+
+# ----------------------------------------------------------------------------------------------------------------------
+# PRELIMINARIES:
+use v5.36;
+use strict;
+use warnings;
+use utf8;
+use Sys::Binmode;
+use Time::HiRes 'time';
+use Math::Combinatorics;
+$"=', ';
+
+# ----------------------------------------------------------------------------------------------------------------------
+# SUBROUTINES:
+sub is_in_list ($item, $list) {
+   for (@$list) {$item eq $_ and return 1;}
+   return 0;
+}
+
+sub remove_from_list ($item, $list) {
+   for ( my $i = 0 ; $i <= $#$list ; ++$i ) {
+      if ($$list[$i] eq $item) {
+         splice @$list, $i, 1;
+         return;
+      }
+   }
+}
+
+sub cant_make($word, $stickers) {
+   my $stck  = join '', @$stickers;
+   my @wordfc = sort split //, fc $word =~ s/\PL//gr;
+   my @stckfc = sort split //, fc $stck =~ s/\PL//gr;
+   for (@wordfc) {
+      if (!is_in_list($_, \@stckfc)) {
+         return 1;
+      }
+   }
+   return 0;
+}
+
+sub can_make($word, $stickers) {
+   my $stck  = join '', @$stickers;
+   my @wordfc = sort split //, fc $word =~ s/\PL//gr;
+   my @stckfc = sort split //, fc $stck =~ s/\PL//gr;
+   for (@wordfc) {
+      if (     is_in_list($_, \@stckfc)) {
+         remove_from_list($_, \@stckfc);
+      }
+      else {
+         return 0;
+      }
+   }
+   return 1;
+}
+
+sub number_of_stickers_needed($word, $stickers) {
+   # If any of the letters of $word are simply NOT IN any of the types
+   # of stickers we have available to us, then return 0, indicating that
+   # "this simply can't be done":
+   if ( cant_make($word, $stickers) ) {
+      return 0;
+   }
+   # Otherwise, we know that this word CAN be made from these sticker types,
+   # though it may take multiple copies of some of the sticker types, up to
+   # a maximum of the number of letters in the word (eg, given word "ddddd"
+   # and stickers ('dog', 'cat', 'pig'), it will take 5 copies of 'dog').
+   my $num_lttrs = length($word);
+   my @multiple;
+   for ( my $j = 1 ; $j <= $num_lttrs ; ++$j ) {
+      push @multiple, @$stickers;
+      my $num_stick = scalar(@multiple);
+      for ( my $i = 1 ; $i <= $num_stick ; ++$i ) {
+         my $combs = Math::Combinatorics->new(count => $i, data => [@multiple]);
+         while ( my @comb = $combs->next_combination ) {
+            can_make($word, \@comb) and return $i;
+         }
+      }
+   }
+   return 0;
+}
+
+# ----------------------------------------------------------------------------------------------------------------------
+# DEFAULT INPUTS:
+my @arrays =
+(
+   [ 'perl', 'raku',    'python', 'peon'          ],
+   [ 'love', 'hate',    'angry',  'goat'          ],
+   [ 'come', 'nation',  'delta',  'accommodation' ],
+   [ 'come', 'country', 'delta',  'accommodation' ],
+);
+
+# ----------------------------------------------------------------------------------------------------------------------
+# NON-DEFAULT INPUTS:
+if (@ARGV) {@arrays = eval($ARGV[0]);}
+
+# ----------------------------------------------------------------------------------------------------------------------
+# MAIN BODY OF PROGRAM:
+{ # begin main
+   my $t0 = time;
+   for my $aref (@arrays) {
+      my @stickers   = @{$aref};
+      my $word       = pop @stickers;
+      my $num_stckrs = number_of_stickers_needed($word, \@stickers);
+      say '';
+      say "word to make     = $word";
+      say "list of stickers = (@stickers)";
+      say "stickers needed  = $num_stckrs";
+   }
+   my $µs = 1000000 * (time - $t0);
+   printf("\nExecution time was %.3fµs.\n", $µs);
+   exit 0;
+} # end main