Challenge 009 task 1

1 files changed, 64 insertions, 0 deletions

diff --git a/challenge-009/jo-37/perl/ch-1.pl b/challenge-009/jo-37/perl/ch-1.pl
new file mode 100755
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+++ b/challenge-009/jo-37/perl/ch-1.pl
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+#!/usr/bin/perl -s
+
+use v5.16;
+use Test2::V0;
+use List::Gen;
+use Math::Prime::Util 'todigits';
+use List::Util 'uniq';
+use experimental 'signatures';
+
+our ($tests, $examples, $base);
+$base ||= 10;
+
+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
+
+-base=B
+    process numbers in base B
+
+N
+    find the first square having at least N different digits in base B.
+
+EOS
+
+
+### Input and Output
+
+say gen_squares(shift, $base)->();
+
+### Implementation
+
+
+# Build a generator for square numbers having at least $n different
+# digits in base $base.
+sub gen_squares ($n, $base) {
+    <1..>->map('**2')->filter(sub{uniq(todigits($_, $base)) >= $n});
+}
+
+### Examples and tests
+
+sub run_tests {
+    SKIP: {
+        skip "examples" unless $examples;
+    }
+
+    SKIP: {
+        skip "tests" unless $tests;
+
+        is gen_squares(5, 10)->take(20),
+        [12769, 13456, 13689, 13924, 15376, 15876, 16384, 17689, 17956,
+            18496, 18769, 20164, 20736, 21609, 21904, 23104, 23409, 23716,
+            28561, 29584], 'from A235720';
+	}
+
+    done_testing;
+    exit;
+}