Firstly, unless explicitly mentioned otherwise, all puzzles have exactly one solution only. As for how to start, just look at 4 consecutive cells in a row/column/diagonal where 3 are already given and are all X (or all O). Then the 4th cell in that row/column/diagonal must be the other sign (Not the one given in all the other 3). If you start at these places, that forms other places where this happens and so on and you can go on solving like that and reach the single solution.

For the competition puzzle in 2009, see the 3rd row, there's an X in the 1st, 2nd and 4th cell. So, by the above explanation, the 3rd cell has to be O, else there'd be 4 Xs in a row.

For the Ripple Effect - I don't get exactly what you mean. Do you mean that the 1s are touching diagonally? If so, they can be next to each other diagonally, the rule only states "same row or column". If you mean something else, is it possible to be clearer? (Maybe post a picture).

For Triangle Count - Given that multiple participants have participated in that Championship that year, if there is any problem, it'd already be reported mostly :) I'm guessing, you might have missed the hidden big triangle, pointing downwards? (There's one big traingle pointing upwards and one of that same size pointing downwards).

For Trid - Consider that digits can't repeat in any straight line. Now look at the competition puzzle, see the "6" sum. The only numbers that can come around it, due to no-repeat rule, are 1,2,3. Since the digit set is 1-6, the maximum sum that 2 adjacent cells can have is 11 (6+5), so the 14 next to the 6 has to have a 3 in the one circle they share, because otherwise, you need more than 11 in the other 2 cells which isn't possible. Use such things, and Sudoku-type eliminations along the straight lines, and you'll get there.

The easiest way to start the competition puzzle of 2009 is to use the 0. Think of it this way - Every cell has a total of 4 lines that can be around it. But no clue can have all 4 lines around it used, because that'll form a little square loop away from the main loop. So, a 0 has to be the number of lines used, rather than unused, because if 0 lines are unused, that means 4 lines are used. Therefore, all 0s have to be inside the loop and have no lines around them. Since the 0 is inside the loop, there needs to be some part of the loop "binding" it on all sides. so, you have a line in the last row, under the 0. This means, the 3 is "bound" as well and is also inside the loop, and there's your start, and you can now also prove that the two 1s are outside the loop and this means that 3 sides of theirs are used by the loop.







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thank you very much prasanna for your valuable reply. :)

hey tel m details dude

By "IPC will be open for a longer period for international players to participate at their own convenience." (IB), what or how long exactly is the period? Can we assume that it's at least 24 hours?

EDIT: More questions as I'm reading the IB:

In F1-F2, can we assume the circle marked A is aligned to some edge of the grid? (This makes seeing which way is clockwise to become easier. Related post.)

In H2, can we assume that we're told which squares are blank? (Just in case the grid is actually a cross or some other thing that is not a rectangle; if we're not told so, the spaces outside the grid can be either a blank square that is supposed to be filled or simply not part of the grid. Currently, the example in the IB has an outlined grid, so the part inside the grid is visible.)



Edited by chaotic_iak 2013-06-30 2:30 PM

For International participation, IPC will be open for 48 hours. When flash submissionis enabled - in a few days from now, local times will be displayed.

"A" will always be the first (top-left-most) black circle. Letters will be marked only on black circle.
However, full points will be awarded if you start from any given letter, and go clock wise / anti clock wise - as long as you enter all letters you should be safe.

Just like the IB, the final puzzle will be a square with borders.

One note about answer key of Battleships :
Answer Key: For each row from top to bottom, enter the column position of left most ship segment. Enter X if no ships.

The word "segment" was missing from the IB.

1. If I understand it right, the A1 questions will be different versions of the ones given in the Instructions booklet, but A2 will be unknown types?

2. Will the Skyscraper Sudoku be a 9x9 or something smaller?

Yes.
Smaller.

IPC Practice Puzzles, Solving Tips, and Links :

http://prasannaseshadri.wordpress.com/2013/07/03/ipc-preview-practi...

does the puzzle quiz contests includes all the various kinds of puzzles? is there any quiz for only sudoku puzzles??

There are annual Championships for Puzzles and Sudoku separately. This year, the Sudoku Championship hasn't been announced yet, but that shouldn't stop you from participating in the Puzzle Championship :)

In H2, is it possible for a word to occur more than once in the grid?

Where can i get some practice puzzles for crosslink(M2)

http://mellowmelon.wordpress.com/category/puzzle-types/slitherlink/...

Regards,
Ravi

For Pentomino Kakuro: Is there any possibility of 6 becoming 9 or 9 becoming 6 during rotation?

No. 6 Remains 6 and 9 remains 9. Only the pieces are rotated, the number (digits) do not change.

No. Each word will appear only once :)

i want to know how to play IPC give me reply

It will be 6X6.

Hi,
I recommend you to go through this link for IPC http://logicmastersindia.com/2013/IPC/
After this if you have any specific questions you can post.

Regards,
Ravi

I solved the Regional Star Battle given in practice pdf by my own and get the differ solution .. .. just check this link. Is it right ??

https://www.dropbox.com/s/nhgkjhszcxnjwxf/20130705_192803_2.jpg