University Studies 3-Fall 2013-Aftermath Fifth meeting (October 31)
 

  • I worked on two puzzles after Thursday's class (using the ipad/iphone app "Enjoy Sudoku"). The first one was a "Practice Puzzle" which is supposed to illustrate the use of X-wings (It does!) The first image below shows the original clues in blue and the result of using basic strategies before filling in all candidates (which was done). Do you see the X-wing? (the relevant digit is highlighted in yellow and pink)
  • CORRECTION (November 13) This is not an X-wing (image1). However, the next one is (image2) (Redemption!)
  • A Practice Sudoku Puzzle (from "Enjoy Sudoku" LEARN X-Wing) (image1)

  • The next image shows further progress. Do you see the new X-wing? (again the relevant digit is highlighted in yellow and pink)
  • A Practice Sudoku Puzzle (from "Enjoy Sudoku" LEARN X-Wing) (image2)

  • The next image shows the progress after implementing the second X-wing. Do you see any X-wings? (I didn't so I used Ariadne's thread to complete the puzzle (see the fourth image). Note how long it took me!
  • A Practice Sudoku Puzzle (from "Enjoy Sudoku" LEARN X-Wing) (image3)
  • Solution to Practice Sudoku Puzzle (from "Enjoy Sudoku" LEARN X-Wing) (image4)

  • The next puzzle I work was classified as "Intricate" by "Enjoy Sudoku". I solved it in 52 minutes but did not use any X-wings, Swordfishes, Jellyfishes, etc. (Go figure!) I also tried a third puzzle but after more than an hour I gave up. Help! Below are the original (Intricate) puzzle and its solution (without using X-wings, etc.)
  • An Intricate Sudoku Puzzle (from "Enjoy Sudoku") (original puzzle)
  • Solution to Intricate Sudoku Puzzle (from "Enjoy Sudoku") (solution)

  • ARE WE HAVING FUN YET?

  • Here are my notes containing the diagrams depicting the examples 13 (X-wing),14 (Swordfish),15 (Jellyfish),16 (Squirmbag) in chapter 7 of Gordon. This might be helpful when doing Sudoku puzzles with pencil.
  • Diagrams illustrating Examples 13,14,15,16 in Chapter 7 of Gordon (pdffile)

  • Here is the (unfinished) Sudoku puzzle that we did together in the seminar. Recall that we only used basic techiques so it was not very useful for practicing with the X-wing family.
  • A puzzle solvable using only basic techniques (Puzzle 71 in Chapter 7 of Gordon) (image)