Merge pull request #5191 from choroba/ech138

Add solutions to 138: Workdays & Split Number by E. Choroba

2 files changed, 73 insertions, 0 deletions

diff --git a/challenge-138/e-choroba/perl/ch-1.pl b/challenge-138/e-choroba/perl/ch-1.pl
new file mode 100755
index 0000000000..f17e160f7f
--- /dev/null
+++ b/challenge-138/e-choroba/perl/ch-1.pl
@@ -0,0 +1,47 @@
+#!/usr/bin/perl
+use warnings;
+use strict;
+use feature qw{ say };
+
+use Time::Piece;
+use Time::Seconds qw{ ONE_DAY };
+
+sub workdays_slow {
+    my ($year) = @_;
+    my $d = 'Time::Piece'->strptime("$year-0101", '%Y-%m%d');
+    my $count = 0;
+    while ($d->year == $year) {
+        my $wday = $d->wday;
+        ++$count if $wday > 1 && $wday < 7;
+        $d += ONE_DAY;
+    }
+    return $count
+}
+
+sub workdays_fast {
+    my ($year) = @_;
+    my $tp = 'Time::Piece'->strptime("$year-0101", '%Y-%m%d');
+    my $wday = $tp->wday;
+    my $leap = $tp->is_leap_year;
+
+    return 260 if $wday == 7 || $wday == 1 && ! $leap;
+    return 262 if $leap && $wday > 1 && $wday < 6;
+    return 261
+}
+
+use Test2::V0;
+
+is workdays_fast(2021), 261, 'Example 1';
+is workdays_fast(2020), 262, 'Example 2';
+
+
+for my $year (1900 .. 2100) {
+    is workdays_slow($year), workdays_fast($year), "same $year";
+}
+done_testing();
+
+use Benchmark qw{ cmpthese };
+cmpthese(-3, {
+    slow => 'workdays_slow(1900 + int rand 1000)',
+    fast => 'workdays_fast(1900 + int rand 1000)',
+});
diff --git a/challenge-138/e-choroba/perl/ch-2.pl b/challenge-138/e-choroba/perl/ch-2.pl
new file mode 100755
index 0000000000..c48f2fde1d
--- /dev/null
+++ b/challenge-138/e-choroba/perl/ch-2.pl
@@ -0,0 +1,26 @@
+#!/usr/bin/perl
+use warnings;
+use strict;
+
+sub _split {
+    my ($sum, $part) = @_;
+    return 1 if $sum == $part;
+
+    for my $length (1 .. length($part) - 1) {
+        my $prefix = substr $part, 0, $length;
+        return 1 if _split($sum - $prefix, substr $part, $length)
+    }
+    return 0
+}
+
+sub split_number {
+    my ($square) = @_;
+    return _split(sqrt $square, $square)
+}
+
+use Test2::V0;
+plan 3;
+
+is split_number(81), 1, 'Example 1';
+is split_number(9801), 1, 'Example 2';
+is split_number(36), 0, 'Example 3';