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| -rwxr-xr-x | challenge-249/jo-37/perl/ch-1.pl | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/challenge-249/jo-37/perl/ch-1.pl b/challenge-249/jo-37/perl/ch-1.pl new file mode 100755 index 0000000000..df8c652043 --- /dev/null +++ b/challenge-249/jo-37/perl/ch-1.pl @@ -0,0 +1,62 @@ +#!/usr/bin/perl -s + +use v5.24; +use Test2::V0; + +our ($tests, $examples); + +run_tests() if $tests || $examples; # does not return + +die <<EOS unless @ARGV; +usage: $0 [-examples] [-tests] [N...] + +-examples + run the examples from the challenge + +-tests + run some tests + +N... + list of numbers + +EOS + + +### Input and Output + +say join ", ", map "(@$_)", equal_pairs(@ARGV); + + +### Implementation + +# Count the frequencies of all given numbers, check if these are all +# even and build equal pairs. + +sub equal_pairs { + my %freq; + $freq{$_}++ for @_; + return () if grep $_ % 2, values %freq; + + map +([$_, $_]) x ($freq{$_} / 2), keys %freq; +} + + +### Examples and tests + +sub run_tests { + SKIP: { + skip "examples" unless $examples; + + is [equal_pairs(3, 2, 3, 2, 2, 2)], + bag {item [2, 2]; item [2, 2]; item [3, 3]; end;}, 'example 1'; + + is [equal_pairs(1, 2, 3, 4)], [] , 'example 2'; + } + + SKIP: { + skip "tests" unless $tests; + } + + done_testing; + exit; +} |
