Issue 1 PUZZLES 2 1 6 5 4 3 Computational Thinking Puzzles 10 9 8 7 A 22 11 11 24 11 8 14 B C 12 10 14 7 19 8 18 5 16 8 8 7 22 12 D 11 4 14 8 16 15 10 2 E 9 6 F 11 19 10 3 14 20 6 11 13 11 19 24 8 1001 0110 G 3 1 11 10 18 9 18 25 8 17 H 0011 1 2 I 24 11 18 15 8 3 9 16 22 19 22 18 A R L J 0001 0010 K 18 3 8 20 3 19 11 Card A 12 L 1100 8 4 21 8 25 22 22 11 19 16 18 11 19 8 M N 14 11 19 10 18 1000 0100 O 12 11 1 22 15 10 10 12 18 10 3 8 P Q 25 11 22 8 23 14 14 R 22 19 11 22 24 22 10 20 21 23 7 10 S T 24 19 8 11 3 10 11 U E V 26 10 15 8 3 11 3 11 26 7 8 19 22 W 7 9 7 14 17 10 8 X Y Z T T H H 0 1 2 3 4 1 Computational thinking puzzles Word search Words can appear in the grid horizontally, vertically or diagonally, running backwards or forwards. Different Computational thinking is a core set of skills that computer scientists develop as names can cross and overlap. they learn to program. It isn’t something you can only learn through programming Find the following famous computer scientists’ names in the word search grid. Their first and second names though. Puzzles can be a great and fun way to develop the skills. This puzzle book may be in different places. Spaces, accents and hyphens are not included. involves a wide range of puzzles that involve aspects of computational thinking. ADA LOVELACE, ANITA BORG, BARBARA LISKOV, DANA ULERY, DOROTHY DENNING, FRAN ALLEN, Some are algorithmic puzzles where the aim is to come up with an algorithm that GRACE HOPPER, JEANNETTE WING, KAREN SPARCK-JONES, MARISSA MAYER, MUFFY CALDER, solves the puzzle. Many like Kakuro and Cut Block puzzles are logic puzzles, that URSULA MARTIN, WENDY HALL are all about logical thinking. To be good at them, though, involves inventing your ALAN TURING, CHRIS STRACHEY, EDGAR CODD, EDSGER DIJKSTRA, JOHN VON NEUMANN, own rules and algorithms for solving them. Yet others, like code cracking grids MAURICE WILKES, MUHAMMAD AL-KHWARIZMI, NIKLAUS WIRTH, PHILIP EMEAGWALI, SERGEY BRIN, involve computing concepts and algorithms in puzzle form. TIM BERNERS-LEE, TONY HOARE, VINT CERF If you enjoy these puzzles more can be found at www.cs4fn.org/puzzles/ Which extra name appears in the grid: a forgotten genius of Bletchley Park? Puzzles are most of all for fun, but it’s always good to be learning useful skills too. N K R E C S N I R U T J E A L U S R U A A E F R E C A C N I U E W V N H O J M R O M A K B R I T M O R N H F B Y V H E A D A L O V E L A C E I M R R S P C N N I W I R T H O O O P K R A I E H L S I J P W E N D Y H A L L E N N R I E P T K K K N V O K S I L A Y I F G L W A A S C H M A U R I S E U A V Z E I N R G T A W E E L T R U M S M R S Y P O C G R O B G E F A J E A N N E T T E D K Y A A N W X G A R D R L A D I M M R J H G I C O D D A Z S T O S L M U E O O T W O O E S O H J G I O S A Z H A G N O N T P I H E D S E N P I C I A G R E R E H R Y E O B A R B A R A R M W A S O U H N C I J P D C G K A L A M A C B D C O I U H E L P M N Y M M W A L E O S T R A C H E Y D E I C R N H D I L R P U D E N N I N G E R O O E K B P E N A W S R E N R E B M U F F Y L R Q E M V O N N E U M A N N T D A N A U A A bit of computational thinking wisdom You may be able to use your natural pattern matching abilities to spot some words. An algorithmic thinking approach may work better though. You need an organised way that is guaranteed to find the words. Take the first letter of a word and start at the top left hand corner, scanning along the rows in turn looking for it. When Solutions you find it check in all directions for the second letter. If its not there move on. If it is look for the third letter Answers to a small selection of the puzzles can be found at the back. in the same direction, and so on. Can you improve this algorithm for solving word searches? Full solutions are at: www.cs4fn.org/puzzles/solutions/ CS4FN Puzzles Issue 1 1 2 3 Cypher breaking grid Cut blocks Crack the cipher by completing the crossword-style grid, and it will reveal one of the greatest movie messages There are two rules that must hold of a completed cut block puzzle. of all time. In a cypher, individual symbols are replaced by new symbols. Here letters have been replaced by numbers. We’ve given you a few letters to start. Use the box at the top to record the key to the cypher. 1) Each area marked out by darker lines must contain the numbers from 1 up to the number of squares in the All letters of the alphabet appear in both the key and grid ... but which is which letter? area. For example, the top most area in the first puzzle below consists of 5 squares so those squares must be filled with the numbers: 1, 2, 3, 4 and 5 with no repeated numbers. If the area has two squares, like the one 1 2 3 4 5 6 7 8 9 10 11 12 13 bottom left below, then it must be filled with the numbers 1 and 2. A 14 15 16 17 18 19 20 21 22 23 24 25 26 2) No number can be next to the same number in any direction, whether horizontally, vertically or diagonally. L R So in the grid below, the fact that there is a 4 on the side means there cannot be a 4 in any of the 5 squares A surrounding it. 22 11 11 24 11 8 14 B Here are two simple cut block puzzles, and then a harder one. 12 10 14 7 19 8 18 5 16 8 8 7 22 C D 4 14 8 16 15 10 2 E F 11 19 10 3 14 20 6 11 13 11 19 24 8 G 2 1 11 10 18 9 18 25 8 17 H I 24 11 18 15 8 3 9 16 22 19 22 18 4 3 A R L J 18 3 8 20 3 19 11 K L 21 8 25 22 22 11 19 16 18 11 19 8 M N 14 11 19 10 18 2 O 5 12 11 1 22 15 10 10 12 18 10 3 8 P Q 25 11 22 8 23 14 14 R 22 19 11 22 24 22 10 20 21 23 7 10 S T 24 19 8 11 3 10 11 U 1 4 V 26 10 15 8 3 11 3 11 26 7 8 19 22 W 3 7 9 7 14 17 10 8 X Y Z 6 14 7 22 12 11 20 8 7 10 10 7 8 20 11 7 24 8 11 18 25 10 16 2 3 5 4 22 20 18 8 11 3 A bit of computational thinking wisdom The great Arab scholar Al-kindi pointed out in the 9th century that you could use frequency analysis to crack A bit of computational thinking wisdom simple cyphers. The most common symbols in the cypher are likely to be the most common letters in English As you fill in numbers, turn what you did into more general rules. Look out for similar situations, pattern and the least common ones the least common letters. matching against your rule, to give you quick ways of filling out the numbers without having to do all the Create a representation of letters used: cross off the letters as you find them.