Solution to task 2

1 files changed, 54 insertions, 0 deletions

diff --git a/challenge-134/jo-37/perl/ch-2.pl b/challenge-134/jo-37/perl/ch-2.pl
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+#!/usr/bin/perl -s
+
+use v5.16;
+use PDL;
+use Test2::V0 '!float';
+use experimental 'signatures';
+
+our $examples;
+
+run_tests() if $examples;	# does not return
+
+die <<EOS unless @ARGV == 2;
+usage: $0 [-examples] [M N]
+
+-examples
+    run the examples from the challenge
+ 
+M N
+    count distinct elements in multiplication table for M and N
+
+EOS
+
+
+### Input and Output
+
+say num_dist_terms(@ARGV[0, 1]);
+
+
+### Implementation
+
+# Calculate the multiplication table as the outer product of two
+# sequences starting with 1, take the unique values thereof and count
+# these.
+# The task description together with its examples is ambiguous:
+# "generate table and display count" I'd take as just to print the
+# count.  OTOH, the examples provide the multiplication table, the
+# distinct terms and the count in the OUTPUT section.  Lazily following
+# the task description.
+
+sub num_dist_terms ($m, $n) {
+    outer(sequence(long, $m) + 1, sequence(long, $n) + 1)->uniq->dim(0);
+}
+
+
+### Examples and tests
+
+sub run_tests {
+
+    is num_dist_terms(3, 3), 6, 'example 1';
+    is num_dist_terms(3, 5), 11, 'example 2';
+
+    done_testing;
+    exit;
+}