A huge book GIVEAWAY!

Here is your chance to win a free book by Djape! 30 books (or more?) are up for grabs! Please check out this post on facebook for details.
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New DJAPE Amazon Brand Store

This is just a quick notice that Amazon and I have created a brand store for all DJAPE products. Click here to see what it is!

Djape Amazon Brand Store
Books by Djape
Posted in General, Puzzle books | Tagged | Leave a comment

Big discounts on some books

Here we go, Amazon has gone crazy again with their promotions and I’m just passing on the information. GIFTBOOK17 promo code for $5 off First, of all, GIFTBOOK17 promo code which you apply on Amazon at checkout to get $5 OFF ANY BOOK is valid only for a few more hours, today November 26, 2017, until midnight, Pacific Time. Conditions apply.
Then, in addition to that promo code, Amazon have decided to give some really good discounts on the following books: These discounts could change at any time – in fact some of them have changed while I was typing this message to you! It must be something about Amazon’s crazy algorithms for discounts, it certainly isn’t me who does that.
Posted in Kakuro, Killer Sudoku, Picross, Puzzle books, Samurai sudoku | Tagged , | 2 Responses

The Return of The Killer Sudoku

UPDATE: You can get $5 off any of my books on Amazon! Use promo code GIFTBOOK17 at checkout. Conditions apply! Valid until November 26. Yeah, that title sounds scary, don’t you think? But before that… Happy Thanksgiving, folks, if you happen to give thanks today! 🙂 So… a first book in the new series of books with killer sudoku puzzles is now published. It is something in between the “Revenge of Killer Sudoku” and “The Deadliest Killer Sudoku” series, at least as far as the difficulty of the puzzles within goes. There are NO EASY, NO COOL puzzles in this book! Difficulty levels are THINKER-BRAIN-IQ-INSANE. The breakout of puzzles is as follows:
  • 100 classic Killer Sudoku 9×9. Half of them are THINKER, 30% are BRAIN, 20% are IQ.
  • Another 10 classic 9×9 Killer Sudokus, all of them INSANE!
  • 10 ZERO Killer Sudoku
  • 10 Killer Sudoku with all four arithmetic operators +,-,*,/
  • and my new personal favorite… 20 Killer Sudokus 10×10, using all 10 digits from 0 to 9!
The book is waiting for you to order. And use that coupon! The price will go up a bit in the next couple of days!
Posted in Killer Sudoku, Puzzle books | Tagged | Leave a comment

Super Quad Sudoku Samurai

I’ve been quiet a little over the past week or so, but now you can expect an avalanche of announcements and newsletters. First up: A new Samurai Sudoku book is out! It’s actually a SUPER Samurai book. This is a new series which will contain more puzzles than the previous Super Samurai Sudoku series of books. Why? Because the last 10 puzzles will be a variety of super samurai, including some LOCO Super Samurai Sudoku puzzles! Anyhow… this book is available to order and ship immediately. Be quick, because in a couple of days the price might go up a little!
Posted in Newsletters, Puzzle books, Samurai sudoku, Washington Post | Tagged | 1 Response

4 books available for pre-order

Here is a novelty: 4 of my books are now available for PRE-ORDER. Important: The price on these books is discounted by about $2 or so. When they get published, which is in about a week’s time, the price will go back to normal. In order of their publishing dates, the books in question are:
  • Super Quad Sudoku Samurai will be published on November 21. It’s a new series of books with Super Samurai Sudoku puzzles and it contains 10 puzzles more than the previous series!
  • Coming up a day later, on November 22, is a book with 150 Killer Sudoku puzzles of medium and hard difficulties: THINKER-BRAIN-IQ-INSANE. It is a new series called “The Return of the Killer Sudoku“. There are a few killer sudoku variants in there. It is not meant to replace neither “the deadliest” series, nor “the revenge” series. It is something in between those two (but somewhat closer to the deadliest killer sudoku series).
  • Then, on November 23, a completely new book with 100 brand new Nonograms-Griddlers-Picross-Hanjie puzzles is released. All puzzles are new, previously unpublished (unlike in the 600 nonograms book).
  • And last, but certainly not the least is the book simply called “Puzzles by Dr Djape“. This book will be released on November 24, 2017 which marks the first anniversary from the date when I defended my PhD thesis. This book contains 100 sudoku variants and 17 other puzzle types, for a total of 300 puzzles altogether. It’s a very special book with very special puzzles. I hope it turns into a series!
Posted in Killer Sudoku, Picross, Puzzle books, Puzzle variants, Samurai sudoku, Sudoku Variants | Tagged , , | 1 Response

Griddlers solving – advanced techniques (Bordering)

A while ago I posted an explanation of an advanced Griddlers/Picross/Nonograms/Hanjie solving technique called Bordering. Here is another example of the bordering technique applied in a different way. Consider this partial nonogram in which only the top few rows are shown. Focus on the first three rows and the “7” clues in them. Where can or cannot this “7” clue in the first row begin? Notice the circled “1” which belongs to column 5. Can the “7” of the first row begin in column 1? It can’t. Why? Because if it did, the “2” in column 2 would also kick off the “7” in row 2, but the “1” in column 5 would stop it before all 7 squares in row 2 are filled, because after the “1” in column 5 there must be a blank square. Get it? Think about it for a while and consider what happens with the perpendicular lines when the “7” of the first row begins right at the start of the row. Continuing this logic, we can conclude the same for the first four squares of row 1 and get to the following position (the red “X”s mean “certain whites”). Now, let’s extend this logic to row 3. Look at all the circled “2”s, which are the first clues (this is extremely important) in their corresponding columns. Looking from the start of row 1, the first two circled “2”s prevent the “7” of row 1 starting anywhere before the “2”s, because the “3” nested between the two “2”s would extend to row 3, but it would be a lonely black square in row 3 because there would be a white to the left and to the right of it, because of the “2”s. Think about it for a while. Finally, now start applying this logic looking from the end of row 1 backwards (right-to-left). The “2”s are circled and should help you conclude that none of the last 7 squares in row 1 can be black and therefore, must be white. Does this make sense to you? Please do comment and/or ask questions if you have any doubts.
Posted in Picross, Solving tips | Leave a comment
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