- Added solutions by Eric Cheung.

- Added solutions by Ulrich Rieke.
- Added solutions by Roger Bell_West.
- Added solutions by Robbie Hatley.
- Added solutions by Simon Green.
- Added solutions by Thomas Kohler.
- Added solutions by Steven Wilson.
- Added solutions by Mark Anderson.
- Added solutions by PokGoPun.
- Added solutions by W. Luis Mochan.
- Added solutions by David Ferrone.
- Added solutions by Peter Campbell Smith.
- Added solutions by E. Choroba.
- Added solutions by Ryan Thompson.
- Added solutions by Matthew Neleigh.
- Added solutions by Dave Jacoby.
- Added solutions by Feng Chang.
- Added solutions by Joelle Maslak.
- Added solutions by Niels van Dijke.
- Added solutions by Mariano Ortega.

16 files changed, 201 insertions, 0 deletions

diff --git a/challenge-276/eric-cheung/python/ch-1.py b/challenge-276/eric-cheung/python/ch-1.py
new file mode 100755
index 0000000000..abb3112347
--- /dev/null
+++ b/challenge-276/eric-cheung/python/ch-1.py
@@ -0,0 +1,12 @@
+

+from itertools import combinations

+

+## arrHours = [12, 12, 30, 24, 24]  ## Example 1

+## arrHours = [72, 48, 24, 5]  ## Example 2

+arrHours = [12, 18, 24]  ## Example 3

+

+arrComb = combinations(arrHours, 2)

+

+arrOutput = [arrLoop for arrLoop in list(arrComb) if sum(arrLoop) % 24 == 0]

+

+print (len(arrOutput))

diff --git a/challenge-276/eric-cheung/python/ch-2.py b/challenge-276/eric-cheung/python/ch-2.py
new file mode 100755
index 0000000000..1f41b77181
--- /dev/null
+++ b/challenge-276/eric-cheung/python/ch-2.py
@@ -0,0 +1,9 @@
+

+## arrInt = [1, 2, 2, 4, 1, 5]  ## Example 1

+arrInt = [1, 2, 3, 4, 5]  ## Example 2

+

+arrFreq = [arrInt.count(nLoop) for nLoop in set(arrInt)]

+

+nMaxFreq = max(arrFreq)

+

+print (nMaxFreq * arrFreq.count(nMaxFreq))

diff --git a/challenge-276/mgo1977/perl/ch1.pl b/challenge-276/mgo1977/perl/ch-1.pl
index 7fbb808b0b..7fbb808b0b 100644
--- a/challenge-276/mgo1977/perl/ch1.pl
+++ b/challenge-276/mgo1977/perl/ch-1.pl
diff --git a/challenge-276/mgo1977/perl/ch2.pl b/challenge-276/mgo1977/perl/ch-2.pl
index 136f80de1a..136f80de1a 100644
--- a/challenge-276/mgo1977/perl/ch2.pl
+++ b/challenge-276/mgo1977/perl/ch-2.pl
diff --git a/challenge-276/perlboy1967/perl/ch1.pl b/challenge-276/perlboy1967/perl/ch-1.pl
index 9ff82133f6..9ff82133f6 100755
--- a/challenge-276/perlboy1967/perl/ch1.pl
+++ b/challenge-276/perlboy1967/perl/ch-1.pl
diff --git a/challenge-276/perlboy1967/perl/ch2.pl b/challenge-276/perlboy1967/perl/ch-2.pl
index d19bebae7e..d19bebae7e 100755
--- a/challenge-276/perlboy1967/perl/ch2.pl
+++ b/challenge-276/perlboy1967/perl/ch-2.pl
diff --git a/challenge-276/ulrich-rieke/cpp/ch-1.cpp b/challenge-276/ulrich-rieke/cpp/ch-1.cpp
new file mode 100755
index 0000000000..2802cb5600
--- /dev/null
+++ b/challenge-276/ulrich-rieke/cpp/ch-1.cpp
@@ -0,0 +1,21 @@
+#include <iostream>

+#include <vector>

+#include <iterator>

+#include <utility>

+#include <algorithm>

+

+int main( ) {

+   std::cout << "Enter some positive integers , separated by blanks, 'e' to end!\n" ;

+   std::vector<int> numbers { std::istream_iterator<int>( std::cin ) , 

+      std::istream_iterator<int>( ) } ;

+   std::vector<std::pair<int , int>> combinations ;

+   int len = numbers.size( ) ;

+   for ( int i = 0 ; i < len - 1 ; i++ ) {

+      for ( int j = i + 1 ; j < len ; j++ ) {

+	 combinations.push_back( std::make_pair( numbers[i] , numbers[j] ) ) ;

+      }

+   }

+   std::cout << std::count_if( combinations.begin( ) , combinations.end( ) , []

+	 ( const auto & p ) { return (p.first + p.second) % 24 == 0 ; } ) << '\n' ;

+   return 0 ;

+}

diff --git a/challenge-276/ulrich-rieke/cpp/ch-2.cpp b/challenge-276/ulrich-rieke/cpp/ch-2.cpp
new file mode 100755
index 0000000000..a3c5d7e345
--- /dev/null
+++ b/challenge-276/ulrich-rieke/cpp/ch-2.cpp
@@ -0,0 +1,29 @@
+#include <vector>

+#include <iostream>

+#include <iterator>

+#include <map>

+

+int main( ) {

+   std::cout << "Enter some integers, separated by blanks, 'e' to end!\n" ;

+   std::vector<int> numbers { std::istream_iterator<int>( std::cin ) , 

+      std::istream_iterator<int>( ) } ;

+   std::map<int , int> frequencies ;

+   for ( int i : numbers ) {

+      frequencies[i]++ ;

+   }

+   int elements = 0 ;//elements with maximum frequency

+   int maximum = 0 ;//maximum frequency

+   for ( auto p : frequencies ) {

+      if ( p.second > maximum ) 

+	 maximum = p.second ;

+   }

+   for ( auto p : frequencies ) {

+      if ( p.second == maximum ) 

+	 elements++ ;

+   }

+   //we want the product of maximum frequency and the number of elements that have it

+   std::cout << elements * maximum << '\n' ;

+   return 0 ;

+}

+

+

diff --git a/challenge-276/ulrich-rieke/haskell/ch-1.hs b/challenge-276/ulrich-rieke/haskell/ch-1.hs
new file mode 100755
index 0000000000..c133891922
--- /dev/null
+++ b/challenge-276/ulrich-rieke/haskell/ch-1.hs
@@ -0,0 +1,18 @@
+module Challenge276

+   where

+import Data.List ( nub , (!!) ) 

+

+combinations :: Int -> [a] -> [[a]]

+combinations 0 _ = [[]]

+combinations n xs = [ xs !! i : x | i <- [0..(length xs ) - 1 ] , 

+ x <- combinations (n - 1 ) ( drop ( i + 1 ) xs ) ]  

+

+solution :: [Int] -> Int

+solution list = length $ filter (\subli -> mod ( sum subli ) 24 == 0 ) $ nub $

+ combinations 2 list

+

+main :: IO ( ) 

+main = do

+   putStrLn "Enter some positive integers, separated by blanks!"

+   numberline <- getLine

+   print $ solution $ map read $ words numberline

diff --git a/challenge-276/ulrich-rieke/haskell/ch-2.hs b/challenge-276/ulrich-rieke/haskell/ch-2.hs
new file mode 100755
index 0000000000..4c06361f5a
--- /dev/null
+++ b/challenge-276/ulrich-rieke/haskell/ch-2.hs
@@ -0,0 +1,19 @@
+module Challenge276_2

+   where

+import Data.List ( sort , sortOn , group ) 

+

+solution :: [Int] -> Int

+solution list = 

+   let sorted = sort list

+       grouped = group sorted

+       groupedLengths = sortOn length grouped

+       maxLen = length $ last groupedLengths -- maximum frequency

+       howmany = length $ filter ( (== maxLen ) . length ) grouped --elements with

+       --maximum frequency

+   in howmany * maxLen --their product    

+

+main :: IO ( )

+main = do

+   putStrLn "Enter some positive integers, separated by blanks!" 

+   numberline <- getLine

+   print $ solution $ map read $ words numberline

diff --git a/challenge-276/ulrich-rieke/perl/ch-1.pl b/challenge-276/ulrich-rieke/perl/ch-1.pl
new file mode 100755
index 0000000000..9fb2cc7793
--- /dev/null
+++ b/challenge-276/ulrich-rieke/perl/ch-1.pl
@@ -0,0 +1,18 @@
+#!/usr/bin/perl ;

+use strict ;

+use warnings ;

+use feature 'say' ;

+use Algorithm::Combinatorics qw ( combinations ) ;

+

+say "Enter some positive integers , separated by blanks!" ;

+my $line = <STDIN> ;

+chomp $line ;

+my @numbers = split( /\s+/ , $line ) ;

+my $total = 0 ;

+my $iter = combinations( \@numbers , 2 ) ;

+while ( my $c = $iter->next ) {

+   if ( ($c->[0] + $c->[1]) % 24 == 0 ) {

+      $total++ ;

+   }

+}

+say $total ;

diff --git a/challenge-276/ulrich-rieke/perl/ch-2.pl b/challenge-276/ulrich-rieke/perl/ch-2.pl
new file mode 100755
index 0000000000..6278f6af18
--- /dev/null
+++ b/challenge-276/ulrich-rieke/perl/ch-2.pl
@@ -0,0 +1,17 @@
+#!/usr/bin/perl ;

+use strict ;

+use warnings ;

+use feature 'say' ;

+use List::Util qw ( max ) ;

+

+say "Enter some integers, separated by blanks!" ;

+my $line = <STDIN> ;

+chomp $line ;

+my @numbers = split( /\s+/ , $line ) ;

+my %frequencies ;

+map { $frequencies{$_}++ } @numbers ;

+my $maximum = max( values( %frequencies ) ) ;

+my $maxElements = scalar( grep { $frequencies{ $_ } == $maximum } keys %frequencies ) ;

+#what we are interested in is the product of maximum frequency and the number of element

+#that are that frequent

+say ( $maxElements * $maximum ) ;

diff --git a/challenge-276/ulrich-rieke/raku/ch-1.raku b/challenge-276/ulrich-rieke/raku/ch-1.raku
new file mode 100755
index 0000000000..5e250b40cc
--- /dev/null
+++ b/challenge-276/ulrich-rieke/raku/ch-1.raku
@@ -0,0 +1,6 @@
+use v6 ;

+

+say "Enter some positive integers, separated by blanks!" ;

+my $line = $*IN.get ;

+my @numbers = $line.words.map( {.Int} ) ;

+say @numbers.combinations( 2 ).grep( { $_.sum %% 24 } ).elems ;

diff --git a/challenge-276/ulrich-rieke/raku/ch-2.raku b/challenge-276/ulrich-rieke/raku/ch-2.raku
new file mode 100755
index 0000000000..246fe012e1
--- /dev/null
+++ b/challenge-276/ulrich-rieke/raku/ch-2.raku
@@ -0,0 +1,14 @@
+use v6 ;

+

+say "Enter some integers, separated by blanks!" ;

+my $line = $*IN.get ;

+my @numbers = $line.words.map( {.Int} ) ;

+my %frequencies ;

+@numbers.map( {%frequencies{$_}++} ) ;

+my $maximum = %frequencies.values.max ;

+my @keys = %frequencies.keys ;

+my $number = @keys.grep( {%frequencies{$_} == $maximum} ).elems ;#number of element

+#with maximum frequency

+#what we look for is the product of maximum frequency and the number of elements that

+#have that maximum frequency!

+say ( $number * $maximum ) ;

diff --git a/challenge-276/ulrich-rieke/rust/ch-1.rs b/challenge-276/ulrich-rieke/rust/ch-1.rs
new file mode 100755
index 0000000000..b743e9bc77
--- /dev/null
+++ b/challenge-276/ulrich-rieke/rust/ch-1.rs
@@ -0,0 +1,15 @@
+use std::io ;
+use itertools::Itertools ;
+
+fn main() {
+    println!("Enter some positive integers, separated by blanks!");
+    let mut inline : String = String::new( ) ;
+    io::stdin( ).read_line( &mut inline ).unwrap( ) ;
+    let entered_line : &str = inline.as_str( ).trim( ) ;
+    let numbers : Vec<u32> = entered_line.split_whitespace( ).map( | s |
+	  s.parse::<u32>( ).unwrap( ) ).collect( ) ;
+    let solution = numbers.into_iter( ).combinations( 2 ).filter( | vec | {
+	  (vec[0] + vec[1]) % 24 == 0 
+	  } ).count( ) ;
+    println!("{}" , solution ) ;
+}
diff --git a/challenge-276/ulrich-rieke/rust/ch-2.rs b/challenge-276/ulrich-rieke/rust/ch-2.rs
new file mode 100755
index 0000000000..f395f112a0
--- /dev/null
+++ b/challenge-276/ulrich-rieke/rust/ch-2.rs
@@ -0,0 +1,23 @@
+use std::io ;
+use std::collections::HashMap ;
+
+fn main() {
+    println!("Enter some positive integers!");
+    let mut inline : String = String::new( ) ;
+    io::stdin( ).read_line( &mut inline ).unwrap( ) ;
+    let entered_line : &str = inline.as_str( ).trim( ) ;
+    let numbers : Vec<u32> = entered_line.split_whitespace( ).map( | s | 
+	  s.parse::<u32>( ).unwrap( ) ).collect( ) ;
+    let mut frequencies : HashMap<u32 , usize> = HashMap::new( ) ;
+    for i in numbers {
+       frequencies.entry( i ).and_modify( |n| {*n += 1} ).or_insert( 1 ) ;
+    }
+    let max_freq : usize = *frequencies.values( ).max( ).unwrap( ) ;
+    let mut number : usize = 0 ; //how many numbers have maximum frequency ?
+    for (_  , v) in &frequencies {
+       if *v == max_freq {
+	  number += 1 ;
+       }
+    }
+    println!("{}" , number * max_freq) ;
+}