This is the archive of the old posts from Djape .Net, more or less as they used to be. Please go to djape.net to see the new website.

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.
Nonograms Griddlers Picross Hanjie book 100 picture puzzles

Posted in Picross, Solving tips | Leave a comment

How To Solve Picross (advanced)

It’s strange that I have never posted any solving techniques for Picross-Hanjie-Griddlers-Nonograms puzzles. I’ve explained some of them in my picross books, but never here on the website. So, that’s about to change and I’m immediately starting with an advanced solving technique, which I call “bordering“. Consider this example (it’s a part of a griddlers puzzle that I’m working on right now). Focus on the two bottom rows and on the corresponding clues. I claim that the cell marked with a red question mark cannot be black, it must remain white. Why? If it were black, the “5” clue, whichever of the two fives it might be, would stretch from this black either to the left or to the right, or a little bit to the left and a bit to the right. Now, see the clues on the top of the image. The clues highlighted in red are all greater than 1 and they are all last clues for the column they apply to. This means that the last patch of blacks in the corresponding columns consist of at least two black cells. In other words, if these patches of blacsk started in the bottom row, they would extend at least to the penultimate row of the puzzle. Get it? Now, if “?” were black, there would be a patch of 5 black cells which would all extend upwards for 2 or more cells, because of the clues on the top. This means that in the penultimate row there would be a patch of 5 cells, too, which must not happen, because the largest clue in the penultimate row is 2! Therefore, the “?” must be white! Get it? But that’s not all! See if you can figure out how many other cells in the bottom row also can’t be black. I will reveal the answer at the bottom of this post. Before that, let me tell you that I’ve published a new book with nonograms puzzles. There are 600 of them in this book! It’s the largest picross book out there. But more about that in a couple of days.

Ok, now, are you ready to see the answer? None of the cells marked with a red X cannot be black, they must be white! The rule for the “bordering” hanjie solving technique can be generalized as follows (are you ready?): If the smallest clue (we’ll call it X) in the bottom row is greater than the largest clue (we’ll call it Y) in the row above it, and if there is a string of at least 2*Y+1 adjacent columns in which the last clue is greater than 1, than the cell in the bottom row which belongs to the column in the middle of the string of Y columns cannot be black, it must be white! Why this term 2*Y+1? Because the “X” clue could come either from the left or from the right, so you need at least twice as many clues plus 1 to get more than Y black adjacent cells in the penultimate row. In my example, X=5, Y=2, and just by chance 2*Y+1=5 (but it doesn’t have to be the same as X). What’s important is that X>Y and that there are at least 2*Y+1 adjacent columns with bottom clues bigger than 1. In my example, there are actually 15 such adjacent columns, but be careful, you cannot put a certain “white” in all of them, only in the middle 15-2*Y. 🙂 Also, this partial puzzle shows that you can apply the same rule twice to the bottom row. There is another string, this time with precisely 5 adjacent columns and now you can mark only one cell as a certain white (5-2*Y). That’s the last red X in the image above. Due to symmetry, the same principle applies to top rows and of course to first and last columns. Study this example and think about it. It should all make sense. Let me know what you think!
Posted in General, Picross, Solving tips | 3 Responses

Clueless LOCO Sudoku

Here is a new puzzle I think you’ll like. It’s another LOCO Sudoku puzzle, however, it is not in Samurai format, but for the first time, it is in Clueless Sudoku format instead. Before you try solving this puzzle, please become familiar with the Clueless Sudoku puzzles and with the Loco Sudoku puzzles, too. Just to help you out with the instructions for this particular puzzle. There are 9 puzzles which all seem to be separate from the rest, each on its own. However, there is a trick! There is also a 10th puzzle which comprises of the 9 central nonets (3×3 boxes) from each of the 9 puzzles. The 10th puzzle is a plain old classic 9×9 Sudoku (aka “vanilla sudoku”). The name “clueless” comes from the fact that the 10th puzzle starts completely clueless (i.e. empty), because all 9 central nonets start without any clues! Get it? Now… since this is a LOCO sudoku variant, I must tell you what the 9 constituent puzzles are:
  • TOP LEFT: jigsaw sudoku
  • TOP CENTER : NON-CONSECUTIVE sudoku (it looks like vanilla but it is not!!!)
  • TOP RIGHT: jigsaw combination sudoku
  • MIDDLE LEFT: hyper sudoku
  • CENTER PUZZLE: diagonal sudoku
  • MIDDLE RIGHT: inequality sudoku (greater-less than)
  • BOTTOM LEFT: consecutive sudoku
  • BOTTOM CENTER : partial odd-even sudoku (shaded=odd, square=even, blank=unknown!)
  • and BOTTOM RIGHT: KILLER sudoku!
Again, I remind you that the 10th puzzle is a plain vanilla sudoku! Are you ready for this!?

Clueless LOCO Sudoku puzzle (Multi Sudoku 9+1 in 1)

To access this puzzle click here.

Posted in Free sample puzzles, Jigsaw Sudoku, Killer Sudoku, Sudoku Variants | Tagged , , | Leave a comment

Puppy Diary and a New Puzzle :)

Here we go… this post is as personal as they get. There is a home video of me in it. And my puppy. And an Instagram post. And a free puzzle. I think I got your attention. Good. If you are wondering why this personal post all of a sudden, you haven’t subscribed to my newsletter yet. Changes are coming to this site. Slowly. So stay tuned and subscribe. It’s free. So I got a Border Collie puppy. Name is Cash. In Serbian language it is pronounced a bit more sharply than in English, you will soon hear me say it a few times. Why Cash? Because “Tango & Cash”. And I dance Tango, a lot. Cash has been with me for 3 weeks now; however, I went sailing for a week and my Mom came over to take care of him. A couple of days after I got him I started clicker training him. I am amazed by his intelligence! Border Collies really are the smartest dog breed around. The video you are about to see was shot a day before Cash’s 3-month birthday. Unfortunately, I give him commands in my language, so you gotta trust me that he does what I tell him to do. If I ever post another video I will try to sound over my comments in English. Anyway… here is the video of me and Cash clicker training at my home. I also posted a short clip of Cash on my Instagram. It was taken 2 days after I got him, before we started training. Now, BACK TO PUZZZZZZLES! I’ve been making Odd Even Sudoku puzzles for years, but this one I’m posting now is a bit different. It contains only PARTIAL Odd Even information. So, not all cells are marked as odd or even as before. Instead, only some of them are labeled. Shaded cells must be Odd. Cells with a square must be Even. No shade, no square? Could be either odd or even! And of course it is not a vanilla Sudoku. It is Partial Odd Even Samurai Sudoku and it’s supposed to be a bit difficult. Here we go:

Partial Odd Even Samurai Sudoku – Overlapping Sudoku Samurai variant – Gattai 5

Click on the puzzle thumbnail to access the puzzle.
Super Sudoku Quad Samurai Puzzle Book with Variants

Posted in General, Samurai sudoku | Tagged , | 6 Responses

New Overlapping Sudoku – Gattai 8

Hey, it’s been a while since my last post… September is the month which marks an anniversary of this website, so I’m gonna start posting more often and possibly, on some non-puzzle related topics. Not sure yet, but it might happen. Stay tuned. Anyhow… Unless I’m mistaken, I haven’t posted a puzzle of this type before. It’s a gattai 8 overlapping sudoku, just like sudoku harakiri, but in a different arrangement of puzzles. Those who like Super Samurai Sudoku or Harakiri Sudoku (by the way, the Harakiri book is currently discounted by $2!!!) will surely like this one. Here it is… it’s labeled IQ for difficulty, but it’s not really all that hard. Oh, I nearly forgot: it requires a heavy use of the Twin Nonets solving technique.

Sudoku Cross – Overlapping Sudoku variant – Gattai 8

To access this puzzle click here.

Posted in Free sample puzzles, Samurai sudoku, Sudoku Variants | Tagged , | 1 Response

Severe server downtime and a free puzzle

This website has been down for nearly 3 weeks. It was an unfortunate mix of extraordinary circumstances, including me being AFK and the provider changing things without notifying me at the same time. Anyway, that’s behind us, everything should be back to normal and in order to celebrate this occasion, I am uploading a new free puzzle for you. It will be another Zero Trigons Puzzle! I strongly recommend you to get to know the trigons puzzles before you attempt this one. Read the rules of trigons and solve a small one. Then, get used to the “pointed tips trigons” and make sure you understand the rule. Finally, try the first Zero Trigons (555) before you try this bigger sibling!

Free Zero Trigons 666 Puzzle

Click on the puzzle thumbnail to access the puzzle.
Big book of big Trigons triangular sudoku trianglons puzzles

Posted in Free sample puzzles, Puzzle variants | Leave a comment

Wendy’s puzzle (triple loco sudoku)

Here we go! It’s been a while since I last posted a free sample puzzle and thanks to Wendy, one of the regular visitors to this website, I am posting a puzzle which I think she’ll like. 🙂 She sent an email saying that in the new volume of the Loco Sudoku book, she preferred the double and triple loco puzzles to those in the samurai format. Well… since that is the case, here is a multi sudoku (aka loco sudoku) triple puzzle consisting of one hyper sudoku, one diagonal sudoku and one consecutive sudoku. Remember, there are three puzzles with three different sets of rules, but the overlapping regions must conform to the rules of the overlapping puzzles. Most overlapping regions follow the rules of two puzzles but the central nonet of the whole puzzle belongs to all three constituent puzzles! Of course, remember to use the Twin Nonets solving technique for this puzzle! How do you like this sudoku variation?

Triple LOCO Sudoku puzzle

Click on the puzzle thumbnail to access the puzzle.
Multi Sudoku LOCO Sudoku, volume 2

Posted in Free sample puzzles, Sudoku Variants | Tagged | 2 Responses

Zero Trigons

Hi folks, it’s been a while! What can I say? I’ll try to be more regular with new puzzle updates, but I can’t promise anything. New puzzle books are coming soon, so stay tuned. Meanwhile, here is a new Trigons puzzle. And it’s first of its kind – it’s a zero trigons! This means that the sum of some trigons is not shown in the puzzle, it is up to you to completely figure them out. Ok, you might need a crash course in trigons. Here are the Trigons rules: Let’s repeat all rules of Trigons: 1. For this puzzle, use digits 0 to 5 to solve it. 2. The numbers given in the puzzle represent the sum of the three digits on the sides of the corresponding triangle. 3. Your goal is to fill in the numbers on the sides so that they add up to the given sum for that trigon (triangle). 4. Numbers CAN BE REPEATED a triangle. 5. Each sum combination MUST BE USED EXACTLY ONCE! All triangle sum combinations are given below the grid so when you use one, cross it off. 6. If a trigon shares only one side with the rest of the puzzle, the other two sides of the trigon must be equal, i.e. must be solved using the same number. Such trigons are called “pointed tips“. 7. If a sum is not shown in a triangle, you must figure it out by eliminating all other possibilities. It still MUST BE ONE OF THE SUMS listed below the grid, and of course, the sum combination cannot be repeated.

Free Zero Trigons Puzzle with pointed tips

Click on the puzzle thumbnail to access the puzzle.
Big book of big Trigons triangular sudoku trianglons puzzles

Does this make the puzzle too difficult? Please share your thoughts.
Posted in Free sample puzzles, Puzzle books, Puzzle variants | 4 Responses

Word Fill-in

Here is my first ever WORD FILL puzzle! After word searches and number searches, a while ago I started creating number fill-ins (and I also published a book of number fill in puzzles). Now is the time to solve my word fill in puzzle. I intend to make many more of Word Fill puzzles in the future. And I will never use 2-letter words and all 3-letter words will actually be words or abbreviations of something. I will strive not to repeat 5-letter and longer words. Most of the words will be “legal” scrabble words and some will be names of animals or geographic terms etc. For example, in this particular puzzle I am posting now, the word which you will start solving with is “dermestid” and it represents a type of a beetle. Look it up on the internet if you like. 🙂 These crossword-like word puzzles are great for improving your vocabulary. Whether you are an avid scrabble player or you just want to build up a good vocab, solving word fill-ins will surely help. The rules are simple: fill the horizontal and vertical fields in the grid with the words listed. All words must be used and can be used only once. No words other than the ones listed can be used. This particular puzzle provides you with an easy “in”: there is only one word with 9 letters, hence it must go into the only 9-letter space in the grid. From there, check the words which can or cannot go into certain fields and fill them in accordingly. DO NOT GUESS! Guessing won’t work most of the time and there is absolutely no need to guess when you solve any of my puzzles, not just word fills. Oh, and one important clarification: fill the grid only with letters A-Z. Punctuation marks shall be skipped. So, for example, the word “Mt. Albert” in this puzzle should be filled in the grid as “MTALBERT”. Please let me know what you think of this particular Word Fill puzzle and if you would like me to change something in the graphics I used.

Free Word Fill-in puzzle

Click on the puzzle thumbnail to access the puzzle.
Large Print Word Fill ins

Posted in Free sample puzzles | Leave a comment

When is Cheryl’s birthday?

It’s been more than two years since I made a post tagged “brain teaser“. In the last few days I’ve seen a couple of interesting brain teasers which went viral on the internet, so it enticed me to posting one of them. It’s called

When is Cheryl’s birthday?

and it’s from some test. It is another exercise in lateral thinking. Here it goes:
Albert and Bernard just become friends with Cheryl, and they want to know when her birthday is. Cheryl gives them a list of 10 possible dates: May 15, May 16, May 19, June 17, June 18, July 14, July 16, August 14, August 15 and August 17. Cheryl then separately tells Albert the month of her birthday and Bernard the day of her birthday. The conversation goes: Albert: “I don’t know when Cheryl’s birthday is, but I know that Bernard does not know either.” Bernard: “At first I didn’t know Cheryl’s birthday, but now I know!” Albert: “Well, then I now also know Cheryl’s birthday!”
And now you know it, too… or do you? 🙂
Posted in General | Tagged , , | 1 Response
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