Merge pull request #7252 from pjcs00/wk195

Week 195 solutions.

3 files changed, 124 insertions, 0 deletions

diff --git a/challenge-195/peter-campbell-smith/blog.txt b/challenge-195/peter-campbell-smith/blog.txt
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+https://pjcs-pwc.blogspot.com/2022/12/some-numbers-are-special-and-others-are.html
diff --git a/challenge-195/peter-campbell-smith/perl/ch-1.pl b/challenge-195/peter-campbell-smith/perl/ch-1.pl
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+#!/usr/bin/perl
+
+# Peter Campbell Smith - 2022-12-12
+# PWC 195 task 1
+
+use v5.28;
+use utf8;
+use warnings;
+
+# You are given a positive integer, $n > 0. Write a script to print the count of all special integers between 1 and $n.
+# An integer is special when all of its digits are unique.
+
+# Blog: https://pjcs-pwc.blogspot.com/2022/12/some-numbers-are-special-and-others-are.html
+
+my (@tests, $test, $count, $j, $digit, $start);
+@tests = (15, 34, 77, 123, 1234, 12345, 1000000, 5000000);
+
+# loop over tests
+say qq[\n--- METHOD 1 ---];
+for $test (@tests) {
+	
+	# loop over 1 to $n
+	$start = time;
+	$count = 0;
+	TEST: for $j (1 .. $test) {
+		
+		# check for 2 of each digit
+		for $digit (0..9) {
+			
+			# don't count if digit repeated
+			next TEST if $j =~ m|$digit.*$digit|;
+		}
+		
+		# is good
+		$count ++;
+	}
+	say qq[\nInput:  $test\nOutput: $count (] . (time - $start) . qq[ secs)];
+}
+
+# loop over tests
+say qq[\n--- METHOD 2 ---];
+for $test (@tests) {
+	
+	# loop over 1 to $n
+	$start = time;
+	$count = 0;
+	$j = 0;
+	
+	while (1) {
+		
+		$j ++;
+		last if $j > $test;
+		if ($j =~ m|(.+?)(0+)$|) {
+			$j = ($1 + 1) * 10 ** length($2) - 1 if unspecial($1);
+		}
+		$count ++ unless unspecial($j);	
+	}
+	say qq[\nInput:  $test\nOutput: $count (] . (time - $start) . qq[ secs)];
+}
+
+sub unspecial {
+	
+	# returns 0 if special, 1 if not
+	return 1 if $_[0] =~ m|1.*1|;
+	return 1 if $_[0] =~ m|2.*2|;
+	return 1 if $_[0] =~ m|3.*3|;
+	return 1 if $_[0] =~ m|4.*4|;
+	return 1 if $_[0] =~ m|5.*5|;
+	return 1 if $_[0] =~ m|6.*6|;
+	return 1 if $_[0] =~ m|7.*7|;
+	return 1 if $_[0] =~ m|8.*8|;
+	return 1 if $_[0] =~ m|9.*9|;
+	return 1 if $_[0] =~ m|0.*0|;
+
+	return 0;
+}
diff --git a/challenge-195/peter-campbell-smith/perl/ch-2.pl b/challenge-195/peter-campbell-smith/perl/ch-2.pl
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+#!/usr/bin/perl
+
+# Peter Campbell Smith - 2022-12-12
+# PWC 195 task 1
+
+use v5.28;
+use utf8;
+use warnings;
+
+# You are given a list of numbers, @list. Write a script to find most frequent even numbers in the list. If
+# you get more than one with the same frequency return the smallest. For all other case, return -1.
+
+# Blog: https://pjcs-pwc.blogspot.com/2022/12/some-numbers-are-special-and-others-are.html
+
+my (@tests, $test, @freq, $max_freq, $max_freq_no, $j, @list);
+
+@tests = ([1,1,2,6,2], [1,3,5,7], [6,4,4,6,1], [23, 46, 72, 15, 0, 33, 34, 72, 1, 99, 1000, 14], 
+	[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0], [1 .. 100], [1, 3, 5, 7, 9, 11, 13,15, 17, 19], [8, 8, 6, 6, 4, 4, 2, 2]);
+
+# loop over tests
+for $test (@tests) {
+	
+	# initialise
+	$max_freq = 0;
+	$max_freq_no = -1;
+	@freq = ();
+	
+	# look at each member of input list, sorted numerically so that we see the smallest first
+	for $j (sort {$a <=> $b} @$test) {
+		
+		# ignore it if it is odd
+		next if $j & 1;
+		
+		# increment its frequency
+		$freq[$j] ++;
+		
+		# if more that the highest seen so far, remember it
+		if ($freq[$j] > $max_freq) {
+			$max_freq = $freq[$j];
+			$max_freq_no = $j;
+		}
+	}
+	
+	# and show the result
+	say qq[\nInput:  \@list = (] . join(', ', @$test) . qq[)\nOutput: $max_freq_no];
+
+}