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| -rw-r--r-- | challenge-191/bob-lied/README | 4 | ||||
| -rw-r--r-- | challenge-191/bob-lied/perl/ch-1.pl | 69 |
2 files changed, 71 insertions, 2 deletions
diff --git a/challenge-191/bob-lied/README b/challenge-191/bob-lied/README index c231e3a589..6fb0b491da 100644 --- a/challenge-191/bob-lied/README +++ b/challenge-191/bob-lied/README @@ -1,3 +1,3 @@ -Solutions to weekly challenge 138 by Bob Lied +Solutions to weekly challenge 191 by Bob Lied -https://perlweeklychallenge.org/blog/perl-weekly-challenge-138/ +https://perlweeklychallenge.org/blog/perl-weekly-challenge-191/ diff --git a/challenge-191/bob-lied/perl/ch-1.pl b/challenge-191/bob-lied/perl/ch-1.pl new file mode 100644 index 0000000000..cdc0d034a1 --- /dev/null +++ b/challenge-191/bob-lied/perl/ch-1.pl @@ -0,0 +1,69 @@ +#!/usr/bin/env perl +# vim:set ts=4 sw=4 sts=4 et ai wm=0 nu: +#============================================================================= +# ch-1.pl Perl Weekly Challenge Task 1 Twice Largest +#============================================================================= +# Copyright (c) 2023, Bob Lied +#============================================================================= +# You are given list of integers, @list. +# Write a script to find out whether the largest item in the list is at least +# twice as large as each of the other items. +# +# Example 1 Input: @list = (1,2,3,4) Output: -1 +# The largest in the given list is 4. # However 4 is not greater than 2*3 +# Example 2 Input: @list = (1,2,0,5) Output: 1 +# The largest in the given list is 5. Also 5 is greater than twice of +# every remaining elements. +# Example 3 Input: @list = (2,6,3,1) Output: 1 +# The largest in the given list is 6. Also 6 is greater than twice of +# every remaining elements. +# Example 4 Input: @list = (4,5,2,3) Output: -1 +# The largest in the given list is 5. But 5 is less than 2*4 and 2*3 +# +# Specification is ambiguous about multiple occurrences of the max. One +# interpretation is that only one copy of max is taken out of the list for +# comparison, meaning that the duplicate will fail the test. The other +# interpretation is that all copies of the maximum value are taken out +# of the list before comparison. +#============================================================================= + +use v5.36; + +use List::Util qw/all/; +use List::MoreUtils qw/after_incl/; + +use Getopt::Long; +my $Verbose = 0; +my $DoTest = 0; + +GetOptions("test" => \$DoTest, "verbose" => \$Verbose); +exit(!runTest()) if $DoTest; + +(my $list = "@ARGV") =~ s/[[:punct:]]/ /g; +say twiceLargest( [ split ' ', $list ] ); + +sub twiceLargest($list) +{ + # Sort to put the max at the front, then shift it off + my @rest = sort { $b <=> $a } $list->@*; + my $max = shift @rest; + + # Handle duplicates of max by excluding all max values. + @rest = after_incl { $_ < $max } @rest; + + return ( all { $max >= 2*$_ } @rest )? 1 : -1; +} + +sub runTest +{ + use Test2::V0; + + is( twiceLargest( [1,2,3,4]), -1, "Example 1"); + is( twiceLargest( [1,2,0,5]), 1, "Example 2"); + is( twiceLargest( [2,6,3,1]), 1, "Example 3"); + is( twiceLargest( [4,5,2,3]), -1, "Example 4"); + is( twiceLargest( [8,8,2,3]), 1, "Dup max"); + + done_testing; +} + |