sgreen solutions to challenge 321

7 files changed, 159 insertions, 2 deletions

diff --git a/challenge-321/sgreen/README.md b/challenge-321/sgreen/README.md
index 030723f69a..10e597d6db 100644
--- a/challenge-321/sgreen/README.md
+++ b/challenge-321/sgreen/README.md
@@ -1,3 +1,3 @@
-# The Weekly Challenge 320
+# The Weekly Challenge 321
 
-Blog: [Words and numbers](https://dev.to/simongreennet/weekly-challenge-the-maximum-difference-2bnm)
+Blog: [Compare the Average](https://dev.to/simongreennet/weekly-challenge-compare-the-average-1907)
diff --git a/challenge-321/sgreen/blog.txt b/challenge-321/sgreen/blog.txt
new file mode 100644
index 0000000000..dda2f7e696
--- /dev/null
+++ b/challenge-321/sgreen/blog.txt
@@ -0,0 +1 @@
+https://dev.to/simongreennet/weekly-challenge-compare-the-average-1907
\ No newline at end of file
diff --git a/challenge-321/sgreen/perl/ch-1.pl b/challenge-321/sgreen/perl/ch-1.pl
new file mode 100755
index 0000000000..4552e44178
--- /dev/null
+++ b/challenge-321/sgreen/perl/ch-1.pl
@@ -0,0 +1,31 @@
+#!/usr/bin/env perl
+
+use bignum;
+use strict;
+use warnings;
+use feature 'say';
+use experimental 'signatures';
+
+use List::Util 'uniq';
+
+sub main (@numbers) {
+    my @averages = ();
+
+    # Make sure the list is even
+    if ( $#numbers % 2 == 0 ) {
+        die "You must provide an even number of numbers\n";
+    }
+
+    # Sort the list, and convert to Decimal type.
+    @numbers = sort { $a <=> $b } @numbers;
+
+    foreach my $idx ( 0 .. scalar(@numbers) / 2 - 1 ) {
+        # Calculate the unique sums for matching pairs
+        push( @averages,
+            ( $numbers[$idx] + $numbers[ $#numbers - $idx ] ) / 2 );
+    }
+
+    say scalar( uniq @averages );
+}
+
+main(@ARGV);
diff --git a/challenge-321/sgreen/perl/ch-2.pl b/challenge-321/sgreen/perl/ch-2.pl
new file mode 100755
index 0000000000..f6d20751fa
--- /dev/null
+++ b/challenge-321/sgreen/perl/ch-2.pl
@@ -0,0 +1,28 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+use experimental 'signatures';
+
+sub convert_string($s) {
+    my $new_string = '';
+    foreach my $c (split //, $s) {
+        if ($c eq '#') {
+            # This is safe even if new_string is empty
+            chop($new_string);
+        }
+        else {
+            $new_string .= $c;
+        }
+    }
+
+    return $new_string;
+}
+
+sub main ($str1, $str2) {
+    my $same = convert_string($str1) eq convert_string($str2);
+    say $same ? 'true' : 'false';
+}
+
+main($ARGV[0], $ARGV[1]);
\ No newline at end of file
diff --git a/challenge-321/sgreen/python/ch-1.py b/challenge-321/sgreen/python/ch-1.py
new file mode 100755
index 0000000000..3851260f4e
--- /dev/null
+++ b/challenge-321/sgreen/python/ch-1.py
@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+
+from decimal import Decimal
+import sys
+
+
+def distinct_average(numbers: list) -> int:
+    unique_averages = set()
+
+    # Make sure the list is even
+    if len(numbers) % 2 == 1:
+        raise ValueError("You must provide an even number of numbers")
+
+    # Sort the list, and convert to Decimal type.
+    numbers = sorted(Decimal(i) for i in numbers)
+
+    for idx in range(len(numbers)//2):
+        # Calculate the unique sums for matching pairs
+        unique_averages.add((numbers[idx] + numbers[-1-idx])/2)
+
+    return len(unique_averages)
+
+
+def main():
+    # Convert input into integers
+    array = [Decimal(n) for n in sys.argv[1:]]
+    result = distinct_average(array)
+    print(result)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/challenge-321/sgreen/python/ch-2.py b/challenge-321/sgreen/python/ch-2.py
new file mode 100755
index 0000000000..81e0d9ed98
--- /dev/null
+++ b/challenge-321/sgreen/python/ch-2.py
@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+
+import sys
+
+def covert_string(s: str) -> str:
+    """Convert a string by treating '#' as a backspace character
+
+    Args:
+        s (str): The original string
+
+    Returns:
+        str: The converted string
+    """
+
+    new_string = ''
+    for c in s:
+        if c == '#':
+            # This is safe even if new_string is empty
+            new_string = new_string[:-1]
+        else:
+            new_string += c
+
+    return new_string
+
+def backspace_compare(str1: str, str2: str) -> bool:
+    """Compare two strings are the same if '#' is a back space character
+
+    Args:
+        str1 (str): The first string
+        str2 (str): The second string
+
+    Returns:
+        bool: Whether the resulting strings are the same
+    """
+    return covert_string(str1) == covert_string(str2)
+
+
+def main():
+    result = backspace_compare(sys.argv[1], sys.argv[2])
+    print(result)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/challenge-321/sgreen/python/test.py b/challenge-321/sgreen/python/test.py
new file mode 100755
index 0000000000..2c353d53a2
--- /dev/null
+++ b/challenge-321/sgreen/python/test.py
@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+
+import unittest
+ch_1 = __import__("ch-1")
+ch_2 = __import__("ch-2")
+
+
+class TestClass(unittest.TestCase):
+    def test_ch_1(self):
+        self.assertEqual(ch_1.distinct_average([1, 2, 4, 3, 5, 6]), 1)
+        self.assertEqual(ch_1.distinct_average([0, 2, 4, 8, 3, 5]), 2)
+        self.assertEqual(ch_1.distinct_average([7, 3, 1, 0, 5, 9]), 2)
+
+    def test_ch_2(self):
+        self.assertTrue(ch_2.backspace_compare("ab#c", "ad#c"))
+        self.assertTrue(ch_2.backspace_compare("ab##", "a#b#"))
+        self.assertFalse(ch_2.backspace_compare("a#b", "c"))
+
+
+if __name__ == "__main__":
+    unittest.main()