Merge pull request #7734 from pjcs00/wk208

Weekly Challenge 208

3 files changed, 121 insertions, 0 deletions

diff --git a/challenge-208/peter-campbell-smith/blog.txt b/challenge-208/peter-campbell-smith/blog.txt
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+++ b/challenge-208/peter-campbell-smith/blog.txt
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+http://ccgi.campbellsmiths.force9.co.uk/challenge/208
diff --git a/challenge-208/peter-campbell-smith/perl/ch-1.pl b/challenge-208/peter-campbell-smith/perl/ch-1.pl
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+++ b/challenge-208/peter-campbell-smith/perl/ch-1.pl
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+#!/usr/bin/perl
+
+# Peter Campbell Smith - 2023-03-13
+
+use v5.28;
+use utf8;
+use warnings;
+
+# You are given two arrays of strings. Write a script to find out all 
+# common strings in the given two arrays with minimum index sum. If no 
+# common strings are found, return an empty list.
+
+# Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge/208/1
+
+my ($j, @list1, @list2);
+
+min_index_sum(["Perl", "Raku", "Love"], ["Raku", "Perl", "Hate"]);
+min_index_sum(['A', 'B', 'C'], ['D', 'E', 'F']);
+min_index_sum(['A', 'B', 'C'], ['C', 'A', 'B']);
+
+# make a longer example - 100 random letters in each list
+for $j (0 .. 99) {
+	$list1[$j] = chr(ord('a') + int(rand(26)));
+	$list2[$j] = chr(ord('a') + int(rand(26)));
+}	
+min_index_sum(\@list1, \@list2);
+	
+sub min_index_sum {
+
+	my (@list1, @list2, $j, %index, $least, $rubric1, $sum, $index1, $index2);
+	
+	@list1 = @{$_[0]};
+	@list2 = @{$_[1]};
+	
+	# make index of first occurrence of word in @list1 - eg $index{"Raku"} == 1
+	for $j (0 .. scalar @list1 - 1) {
+		$index{$list1[$j]} = $j unless $index{$list1[$j]};
+	}
+	
+	# scan through @list2
+	$least = 10^6;
+	$rubric1 = '';
+	for $index2 (0 .. scalar @list2 - 1) {
+		last if $index2 > $least;
+		$index1 = $index{$list2[$index2]};
+		
+		# is this $list2 word in @list1?
+		if (defined $index1) {
+			$sum = $index1 + $index2;
+			next if $sum > $least;
+			
+			# found a lesser sum of indices
+			$rubric1 = '' if $sum < $least;
+			$least = $sum;
+			$rubric1 .= qq["$list2[$index2]", ];
+		}
+	}
+	
+	# show the answers
+	say qq[\nInput:  \@list1 = ("] . join('", "', @list1) . q[")];
+	say qq[        \@list2 = ("] . join('", "', @list2) . q[")];
+	say qq[Output: (] . substr($rubric1, 0, -2) . q[)];	
+}	
+
diff --git a/challenge-208/peter-campbell-smith/perl/ch-2.pl b/challenge-208/peter-campbell-smith/perl/ch-2.pl
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+++ b/challenge-208/peter-campbell-smith/perl/ch-2.pl
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+#!/usr/bin/perl
+
+# Peter Campbell Smith - 2023-03-13
+
+use v5.28;
+use utf8;
+use warnings;
+
+# You are given an array of integers in sequence with one missing and one duplicate.
+# Write a script to find the duplicate and missing integer in the given array. 
+# Return -1 if none found. You may assume the array contains no more than one duplicate 
+# and missing.
+
+# Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge/208/2
+
+dup_and_miss(1, 2, 3, 3, 5);
+dup_and_miss(7, 7, 8, 9, 11);
+dup_and_miss(7, 8, 9, 11, 11);
+dup_and_miss(4, 5, 6, 7, 8, 8, 9, 10, 11, 12, 13, 15);
+dup_and_miss(1, 2, 3, 4, 5);
+
+sub dup_and_miss {
+	
+	my (@list, $j, $duplicate, $missing);
+	
+	@list = @_;
+	
+	# scan through the list up to the second last entry
+	for $j (0 .. scalar @list - 2) {
+		
+		# if this one is the same as the next one, then this one's a duplicate
+		if ($list[$j] == $list[$j + 1]) {
+			invalid(@list) if $duplicate;
+			$duplicate = $list[$j];
+		
+		# if this one is 2 less than the next one, then this one plus one is missing		
+		} elsif ($list[$j] + 2 == $list[$j + 1]) {
+			invalid(@list) if $missing;
+			$missing = $list[$j] + 1;
+			
+		# or the list is invalid
+		} elsif ($list[$j] + 1 != $list[$j + 1]) {
+			invalid(@list);
+		}
+	}
+
+	say qq[\nInput:  \@nums = (] . join(', ', @list) . q[)];
+	say qq[Output: ] . ((defined $duplicate and defined $missing) ? 
+		qq[Duplicate is $duplicate and Missing is $missing.] : -1);
+}
+
+sub invalid {
+	say qq[\nInvalid input: \@list = (] . join(', ', @_) . q[)];
+	exit;
+}
+