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| -rw-r--r-- | challenge-053/luca-ferrari/raku/ch-2.p6 | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/challenge-053/luca-ferrari/raku/ch-2.p6 b/challenge-053/luca-ferrari/raku/ch-2.p6 new file mode 100644 index 0000000000..6bdc1bb388 --- /dev/null +++ b/challenge-053/luca-ferrari/raku/ch-2.p6 @@ -0,0 +1,77 @@ +#!env raku +# +# Perl Weekly Challenge 53 +# <https://perlweeklychallenge.org/blog/perl-weekly-challenge-053/> +# +# Task 2 +# +# Write a script to accept an integer 1 <= N <= 5 that would +# print all possible strings of size N formed +# by using only vowels (a, e, i, o, u). +# +# The string should follow the following rules: +# +# ‘a’ can only be followed by ‘e’ and ‘i’. +# +# ‘e’ can only be followed by ‘i’. +# +# ‘i’ can only be followed by ‘a’, ‘e’, ‘o’, and ‘u’. +# +# ‘o’ can only be followed by ‘a’ and ‘u’. +# +# ‘u’ can only be followed by ‘o’ and ‘e’. +# +# For example, if the given integer N = 2 then script +# should print the following strings: +# +# ae +# ai +# ei +# ia +# io +# iu +# ie +# oa +# ou +# uo +# ue +# + + + +sub MAIN( Int:D $size where { 1 < $size <= 5 } = 2 ) { + say "Requested string length is $size "; + my @vowels = 'a', 'e', 'i', 'o', 'u'; + + # build a matrix with all the possibile combinations + my @combinations = @vowels; + for 1 ..^ $size { + @combinations = @combinations [X] @vowels; + } + + + + for @combinations -> @letters { + my $string = @letters.join; + my $ok = True; + + # test if all but the last letters do match the regular expression + loop ( my $i = 0; $i < @letters.elems - 1; $i++ ) { + my $letter = @letters[ $i ]; + $ok = do + given $letter { + when 'a' { $string ~~ / a (e | i) / } + when 'e' { $string ~~ / ei / } + when 'i' { $string ~~ / i ( a | e | o | u ) / } + when 'o' { $string ~~ / o ( a | u ) / } + when 'u' { $string ~~ /u ( o | e ) / } + }.so; + + # if not ok, do not continue + last if ! $ok; + } + + say "Found { ~@letters }" if $ok; + } + +} |