Merge pull request #7459 from pjcs00/wk201

week 201 submission

1 files changed, 52 insertions, 0 deletions

diff --git a/challenge-201/peter-campbell-smith/perl/ch-2.pl b/challenge-201/peter-campbell-smith/perl/ch-2.pl
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+#!/usr/bin/perl
+
+# Peter Campbell Smith - 2023-01-23
+# PWC 201 task 2
+
+use v5.28;
+use utf8;
+use warnings;
+
+# Task: You are given an integer, $n > 0. Write a script to determine the number of ways of putting $n 
+# pennies in a row of piles such that each pile contains no fewer pennies than the one on its left.
+
+# Blog: https://pjcs-pwc.blogspot.com/2023/01/201-missing-numbers-and-piles-of-pennies.html
+
+my (@tests, $n, $ways, $piles);
+
+@tests = (1, 2, 3, 4, 5, 20);
+
+# loop over tests
+for $n (@tests) {
+	
+	# initialise
+	$ways = 0;
+	$piles = '';
+	
+	# find possible ways to do it
+	find_ways($n, $n, '');
+	
+	# output results
+	say qq[Input:  \$n = $n\nOutput: ] . $ways;
+	say qq[Piles:\n$piles];
+}	
+
+sub find_ways {
+	
+	# returns the number of possible ways of stacking $pennies pennies in stacks no more than $height
+	my ($pennies, $height, $stack) = @_;
+	my ($h);
+
+	# no pennies left - answer found
+	if ($pennies == 0) {
+		$piles .= qq[$stack\n];
+		$stack = '';
+		$ways ++;
+		return;
+	}
+	
+	# loop over possible piles
+	for $h (1 .. ($pennies > $height ? $height : $pennies)) {
+		find_ways($pennies - $h, $h, qq[$h $stack]);
+	}
+}