Add Perl solution to challenge 054

6 files changed, 121 insertions, 0 deletions

diff --git a/challenge-054/paulo-custodio/Makefile b/challenge-054/paulo-custodio/Makefile
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+++ b/challenge-054/paulo-custodio/Makefile
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+all:
+	perl ../../challenge-001/paulo-custodio/test.pl
diff --git a/challenge-054/paulo-custodio/README b/challenge-054/paulo-custodio/README
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+Solution by Paulo Custodio
diff --git a/challenge-054/paulo-custodio/perl/ch-1.pl b/challenge-054/paulo-custodio/perl/ch-1.pl
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+++ b/challenge-054/paulo-custodio/perl/ch-1.pl
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+#!/usr/bin/env perl
+
+# Challenge 054
+#
+# TASK #1
+# kth Permutation Sequence
+# Write a script to accept two integers n (>=1) and k (>=1). It should print the
+# kth permutation of n integers. For more information, please follow the wiki
+# page.
+#
+# For example, n=3 and k=4, the possible permutation sequences are listed below:
+#
+# 123
+# 132
+# 213
+# 231
+# 312
+# 321
+# The script should print the 4th permutation sequence 231.
+
+use Modern::Perl;
+use Math::Combinatorics;
+
+my($n, $k) = @ARGV;
+my @data = (1..$n);
+my $combinat = Math::Combinatorics->new(count => $k, data => \@data);
+while (my @permu = $combinat->next_permutation) {
+    say @permu;
+}
diff --git a/challenge-054/paulo-custodio/perl/ch-2.pl b/challenge-054/paulo-custodio/perl/ch-2.pl
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+#!/usr/bin/env perl
+
+# Challenge 054
+#
+# TASK #2
+# Collatz Conjecture
+# Contributed by Ryan Thompson
+# It is thought that the following sequence will always reach 1:
+#
+# $n = $n / 2 when $n is even
+# $n = 3*$n + 1 when $n is odd
+# For example, if we start at 23, we get the following sequence:
+#
+# 23 ? 70 ? 35 ? 106 ? 53 ? 160 ? 80 ? 40 ? 20 ? 10 ? 5 ? 16 ? 8 ? 4 ? 2 ? 1
+#
+# Write a function that finds the Collatz sequence for any positive integer.
+# Notice how the sequence itself may go far above the original starting number.
+#
+# Extra Credit
+# Have your script calculate the sequence length for all starting numbers up to
+# 1000000 (1e6), and output the starting number and sequence length for the
+# longest 20 sequences.
+
+use Modern::Perl;
+
+my @longest;
+for my $n (1..1e6) {
+    my @seq = collatz($n);
+    my $len = scalar(@seq);
+    push @longest, [$n => $len];
+    @longest = sort {$b->[1] <=> $a->[1]} @longest;
+    pop @longest if @longest > 20;
+}
+
+for (@longest) {
+    my($n, $len) = @$_;
+    say "$n $len";
+}
+
+sub collatz {
+    my($n) = @_;
+    my @out = ($n);
+    while ($n != 1) {
+        if ($n%2==0) {
+            $n /= 2;
+        }
+        else {
+            $n = 3*$n+1;
+        }
+        push @out, $n;
+    }
+    return @out;
+}
diff --git a/challenge-054/paulo-custodio/t/test-1.yaml b/challenge-054/paulo-custodio/t/test-1.yaml
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index 0000000000..4f1abdea10
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+++ b/challenge-054/paulo-custodio/t/test-1.yaml
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+- setup:
+  cleanup:
+  args:     3 3
+  input:
+  output:   |
+            |123
+            |132
+            |213
+            |231
+            |312
+            |321
diff --git a/challenge-054/paulo-custodio/t/test-2.yaml b/challenge-054/paulo-custodio/t/test-2.yaml
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+++ b/challenge-054/paulo-custodio/t/test-2.yaml
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+- setup:
+  cleanup:
+  args:     20
+  input:
+  output:   |
+            |837799 525
+            |626331 509
+            |939497 507
+            |704623 504
+            |910107 476
+            |927003 476
+            |511935 470
+            |767903 468
+            |796095 468
+            |970599 458
+            |546681 452
+            |818943 450
+            |820022 450
+            |820023 450
+            |410011 449
+            |615017 447
+            |886953 445
+            |906175 445
+            |922524 445
+            |922525 445