Merge pull request #9247 from simongreen-net/master

Simon's solution to challenge 245 and 247

13 files changed, 334 insertions, 7 deletions

diff --git a/challenge-245/sgreen/README.md b/challenge-245/sgreen/README.md
index fb592c5c30..ba6bc079ce 100644
--- a/challenge-245/sgreen/README.md
+++ b/challenge-245/sgreen/README.md
@@ -1,3 +1,3 @@
-# The Weekly Challenge 244
+# The Weekly Challenge 245
 
-Blog: [Weekly Challenge 244](https://dev.to/simongreennet/weekly-challenge-244-jim)
+Blog: [Sorting by threes](https://dev.to/simongreennet/sorting-by-threes-ocf)
diff --git a/challenge-245/sgreen/blog.txt b/challenge-245/sgreen/blog.txt
new file mode 100644
index 0000000000..41beaed6c6
--- /dev/null
+++ b/challenge-245/sgreen/blog.txt
@@ -0,0 +1 @@
+https://dev.to/simongreennet/sorting-by-threes-ocf
\ No newline at end of file
diff --git a/challenge-245/sgreen/perl/ch-1.pl b/challenge-245/sgreen/perl/ch-1.pl
new file mode 100755
index 0000000000..d2fcf98fe9
--- /dev/null
+++ b/challenge-245/sgreen/perl/ch-1.pl
@@ -0,0 +1,29 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+use experimental 'signatures';
+
+use List::Util 'zip';
+
+sub main (@inputs) {
+    # We need an even number of inputs
+    if ( scalar(@inputs) % 2 == 1 ) {
+        die "We require an even number of inputs\n";
+    }
+
+    # Split the input into words and places
+    my $half   = scalar(@inputs) / 2;
+    my @words  = @inputs[ 0 .. $half - 1 ];
+    my @places = @inputs[ $half .. $#inputs ];
+
+    # Create a dict where the key is the place, and the value is the word
+    my %rankings = ( map { @$_ } zip( \@places, \@words ) );
+
+    # Order the words by their ranking
+    my @solution = ( map { $rankings{$_} } sort { $a <=> $b } keys %rankings );
+    say join ', ', @solution;
+}
+
+main(@ARGV);
\ No newline at end of file
diff --git a/challenge-245/sgreen/perl/ch-2.pl b/challenge-245/sgreen/perl/ch-2.pl
new file mode 100755
index 0000000000..8055448867
--- /dev/null
+++ b/challenge-245/sgreen/perl/ch-2.pl
@@ -0,0 +1,44 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+use experimental 'signatures';
+
+use Algorithm::Combinatorics 'permutations';
+use List::Util 'sum';
+
+sub largest_number (@numbers) {
+    # Calculate the largest number using the all supplied numbers
+    my $largest = 0;
+    my $iter    = permutations( \@numbers );
+    while ( my $i = $iter->next ) {
+        my $n = join( '', @$i );
+        if ( $n > $largest ) {
+            $largest = $n;
+        }
+    }
+
+    return $largest;
+}
+
+sub main (@ints) {
+    my $largest = -1;
+    foreach my $bitwise ( 1 .. 2**scalar(@ints) - 1 ) {
+        my @numbers =
+          ( map { $ints[$_] } grep { $bitwise & ( 2**$_ ) } ( 0 .. $#ints ) );
+        if ( sum(@numbers) % 3 != 0 ) {
+            # There is no possible solution with this set of numbers
+            next;
+        }
+
+        my $this_largest = largest_number(@numbers);
+        if ( $this_largest > $largest ) {
+            $largest = $this_largest;
+        }
+    }
+
+    say $largest;
+}
+
+main(@ARGV);
\ No newline at end of file
diff --git a/challenge-245/sgreen/python/ch-1.py b/challenge-245/sgreen/python/ch-1.py
new file mode 100755
index 0000000000..a39f9980eb
--- /dev/null
+++ b/challenge-245/sgreen/python/ch-1.py
@@ -0,0 +1,29 @@
+#!/usr/bin/env python3
+
+import sys
+
+
+def main(words, places):
+    # Create a dict where the key is the place, and the value is the word
+    rankings = {
+        place: word for place, word in zip(places, words)
+    }
+
+    # Order the words by their ranking
+    solution = [rankings[place] for place in sorted(rankings)]
+    print(*solution, sep=', ')
+
+
+if __name__ == '__main__':
+    inputs = sys.argv[1:]
+
+    # We need an even number of inputs
+    if len(inputs) % 2 == 1:
+        raise ValueError('We require an even number of inputs')
+
+    # Split the input into words and places
+    half = len(inputs) // 2
+    words = inputs[:half]
+    # Convert input into integers
+    places = [int(n) for n in inputs[half:]]
+    main(words, places)
diff --git a/challenge-245/sgreen/python/ch-2.py b/challenge-245/sgreen/python/ch-2.py
new file mode 100755
index 0000000000..20098f5788
--- /dev/null
+++ b/challenge-245/sgreen/python/ch-2.py
@@ -0,0 +1,36 @@
+#!/usr/bin/env python3
+
+from itertools import permutations
+import sys
+
+
+def largest_number(numbers):
+    # Calculate the largest number using the all supplied numbers
+    largest = 0
+    for i in permutations(map(lambda x: str(x), numbers)):
+        n = int(''.join(i))
+        if n > largest:
+            largest = n
+
+    return largest
+
+
+def main(ints):
+    largest = -1
+    for bitwise in range(1, 2 ** len(ints)):
+        numbers = [n for i, n in enumerate(ints) if bitwise & (2 ** i)]
+        if sum(numbers) % 3 != 0:
+            # There is no possible solution with this set of numbers
+            continue
+
+        this_largest = largest_number(numbers)
+        if this_largest > largest:
+            largest = this_largest
+
+    print(largest)
+
+
+if __name__ == '__main__':
+    # Convert input into integers
+    array = [int(n) for n in sys.argv[1:]]
+    main(array)
diff --git a/challenge-246/sgreen/README.md b/challenge-246/sgreen/README.md
deleted file mode 100644
index fb592c5c30..0000000000
--- a/challenge-246/sgreen/README.md
+++ /dev/null
@@ -1,3 +0,0 @@
-# The Weekly Challenge 244
-
-Blog: [Weekly Challenge 244](https://dev.to/simongreennet/weekly-challenge-244-jim)
diff --git a/challenge-247/sgreen/README.md b/challenge-247/sgreen/README.md
index fb592c5c30..191a192e6e 100644
--- a/challenge-247/sgreen/README.md
+++ b/challenge-247/sgreen/README.md
@@ -1,3 +1,3 @@
-# The Weekly Challenge 244
+# The Weekly Challenge 247
 
-Blog: [Weekly Challenge 244](https://dev.to/simongreennet/weekly-challenge-244-jim)
+Blog: [The one about frequency](https://dev.to/simongreennet/the-one-about-frequency-la6)
diff --git a/challenge-247/sgreen/blog.txt b/challenge-247/sgreen/blog.txt
new file mode 100644
index 0000000000..f76ab26514
--- /dev/null
+++ b/challenge-247/sgreen/blog.txt
@@ -0,0 +1 @@
+https://dev.to/simongreennet/the-one-about-frequency-la6
\ No newline at end of file
diff --git a/challenge-247/sgreen/perl/ch-1.pl b/challenge-247/sgreen/perl/ch-1.pl
new file mode 100755
index 0000000000..91b6fd58ef
--- /dev/null
+++ b/challenge-247/sgreen/perl/ch-1.pl
@@ -0,0 +1,70 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+use experimental 'signatures';
+
+sub get_person ( $family_members, $exclude ) {
+    # Sort the family dict by frequency, largest first
+    my @sorted_surname = sort {
+        scalar( @{ $family_members->{$b} } ) <=>
+          scalar( @{ $family_members->{$a} } )
+    } keys %$family_members;
+
+    # If we want to exclude a surname, chose the second option if the exclude
+    #  name is first, and there is a second option
+    if (    $exclude
+        and $sorted_surname[0] eq $exclude
+        and $#sorted_surname > 0
+        and scalar( @{ $family_members->{ $sorted_surname[1] } } ) > 0 )
+    {
+        return $sorted_surname[1];
+    }
+
+    return $sorted_surname[0];
+}
+
+sub get_surname ($name) {
+    my $i = rindex( $name, ' ' );
+    if ( $i != -1 ) {
+        return substr( $name, $i + 1 );
+    }
+
+    # A person with nothing before their surname
+    return $name;
+}
+
+sub main (@people) {
+    my @chain = ();
+
+    # Calculate the frequency of each family
+    my %family_members = ();
+    foreach my $p (@people) {
+        my $surname = get_surname($p);
+        push @{ $family_members{$surname} }, $p;
+    }
+
+    # Get the first person, and seed the chain
+    my $current_surname = get_person( \%family_members, undef );
+    my $first_person    = pop( @{ $family_members{$current_surname} } );
+    push @chain, $first_person;
+
+    foreach ( 1 .. $#people ) {
+        my $next_surname = get_person( \%family_members, $current_surname );
+        push @chain, shift( @{ $family_members{$next_surname} } );
+
+        # Repeat for the next person
+        $current_surname = $next_surname;
+    }
+
+    # The last person gives to the first person
+    push @chain, $chain[0];
+
+    # Print the results
+    foreach my $i ( 0 .. $#people ) {
+        say "$chain[$i] -> $chain[$i+1]";
+    }
+}
+
+main(@ARGV);
\ No newline at end of file
diff --git a/challenge-247/sgreen/perl/ch-2.pl b/challenge-247/sgreen/perl/ch-2.pl
new file mode 100755
index 0000000000..05520f9c32
--- /dev/null
+++ b/challenge-247/sgreen/perl/ch-2.pl
@@ -0,0 +1,31 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+use experimental 'signatures';
+
+sub main ($string) {
+    # The alphabet
+    my $alphabet = join '', 'a' .. 'z';
+
+    # Store the best result found
+    my $solution    = undef;
+    my $occurrences = 0;
+
+    foreach my $i ( 0 .. 24 ) {
+        # Get the two consecutive letters and the number of occurrences
+        my $letters = substr( $alphabet, $i, 2 );
+        my $count   = () = $string =~ /$letters/g;
+
+        # If it is greater than the current count, store it
+        if ( $count > $occurrences ) {
+            $occurrences = $count;
+            $solution    = $letters;
+        }
+    }
+
+    say $solution // "No consecutive letters found!";
+}
+
+main( $ARGV[0] );
\ No newline at end of file
diff --git a/challenge-247/sgreen/python/ch-1.py b/challenge-247/sgreen/python/ch-1.py
new file mode 100755
index 0000000000..14a0595cb2
--- /dev/null
+++ b/challenge-247/sgreen/python/ch-1.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+
+import sys
+
+
+def get_person(family_members, exclude=None):
+    # Sort the family dict by frequency, largest first
+    sorted_surname = sorted(
+        family_members,
+        key=lambda i: len(family_members[i]),
+        reverse=True
+    )
+
+    # If we want to exclude a surname, chose the second option if the exclude
+    #  name is first, and there is a second option
+    if exclude and sorted_surname[0] == exclude and len(sorted_surname) > 1 \
+            and len(family_members[sorted_surname[1]]) > 0:
+        return sorted_surname[1]
+
+    return sorted_surname[0]
+
+
+def get_surname(name):
+    i = name.rfind(' ')
+    if i is not None:
+        return name[i+1:]
+    else:
+        return name
+
+
+def main(people):
+    # Calculate the frequency of each family
+    family_members = {}
+    for p in people:
+        surname = get_surname(p)
+        if surname not in family_members:
+            family_members[surname] = []
+        family_members[surname].append(p)
+
+    # Get the first person, and seed the chain
+    current_surname = get_person(family_members)
+    first_person = family_members[current_surname].pop()
+    chain = [first_person]
+
+    for _ in range(len(people)-1):
+        next_surname = get_person(family_members, current_surname)
+        chain.append(family_members[next_surname].pop())
+        # Repeat for the next person
+        current_surname = next_surname
+
+    # The last person gives to the first person
+    chain.append(chain[0])
+
+    # Print the results
+    for i in range(len(people)):
+        print(f'{chain[i]} -> {chain[i+1]}')
+
+
+if __name__ == '__main__':
+    main(sys.argv[1:])
diff --git a/challenge-247/sgreen/python/ch-2.py b/challenge-247/sgreen/python/ch-2.py
new file mode 100755
index 0000000000..f108d2e7bf
--- /dev/null
+++ b/challenge-247/sgreen/python/ch-2.py
@@ -0,0 +1,29 @@
+#!/usr/bin/env python3
+
+import sys
+import string
+
+
+def main(s):
+    # The alphabet
+    alphabet = string.ascii_lowercase
+
+    # Store the best result found
+    solution = None
+    occurrences = 0
+
+    for i in range(25):
+        # Get the two consecutive letters and the number of occurrences
+        letters = alphabet[i:i+2]
+        count = s.count(letters)
+
+        # If it is greater than the current count, store it
+        if count > occurrences:
+            occurrences = count
+            solution = letters
+
+    print(solution or "No consecutive letters found!")
+
+
+if __name__ == '__main__':
+    main(sys.argv[1])