As a participant of all five world championships, I can say that this will be evoking memories of five more or less beautiful destinations, nice fellowship and fun. The only thing which appeared in the booklet, but has not happened is that in Prague there wasn't classic sudoku, not even in team parts. Actually, there was one in the opening part, but it was called Picture.

I have a question about, for me, frustrating time bonus. Is it possible to know exactly how many points will be given for each puzzle in each time segment? For example, puzzle A1 is 19 points until 70 minutes, but how many points is if I complete task between 90-105 minutes? I would like to know the values for all grids and all periods. Thanks!

Nikola

Edited by Nikola 2011-07-13 12:38 PM

Detailed point reductions can be seen below

Interesting.... Looks like will have to change strategy of updating answers at the end... Finish a puzzle and update answer... :)

Definitely yes after 70 minutes.

Unlike in Twist, points start reducing much earlier here. So I guess it is equally important to make a strategy for 'order of solving'

the best strategy would be to solve the high pointers and submit in the first 70 minutes and then solve the low pointers.

Distance sudoku :
it is given that " clues outside the grid represent the distances between the given digits for the corresponding directions, in order."
But seeing the solution the number itself is also included for distance.

quadruple sudoku
solution is not given . and are the given numbers enough to complete the sudoku.

i am finding the B part of this test very tough to start. IS that the puzzle given itself is tough or i am missing some trick to do that puzzles.


Agree. But there is high risk involved as well - if you are unable to solve, you get zero points and lose a lot of time too.

No Pain No Gain

No risk, No gain

If distance is given as N, it means there are N-1 numbers between the two given numbers.


solution is not given because the given numbers are not enough to complete the sudoku.

As mentioned in IB, all examples are from the official IBs. And if I remember correctly, this is how it appeared in the corresponding IB as well.

Here is a complete Quadruple sudoku if you need practice (Note that digits may repeat in the 4 cells. This example doesn't have such a case)



Solution

For a particular sudoku, I submit a correct answer at 65 minutes. Then I think something is wrong, so I change the answer and submit an incorrect answer at 75 minutes. But, in the end, I again realize my mistake and re-submit the correct answer at 119 minutes. The puzzle is worth 100 points.

How many do I get - 100 or 50?

Technically 50.... since the last time stamp associated with that puzzle will show a time of 119 minutes....

Rishi

An even better strategy would be to solve all grids in the first 70 minutes

Simplest strategy, not sure why others couldn't come up with this idea

Maybe some people are realistic and know their limitations :D

Is this test designed so the best solvers can finish them all within 70 minutes?

I thought originally the idea of the time expansion/points reduction concept was so more people could have the time to finish all puzzles, at least i thought that's why it was brought up at least. It just gives me a small idea of the average difficulty of all puzzles. As if it is, I might approach it with the mindset of being able to finish all puzzles(which I generally don't expect to acchieve in a sudoku contest), as i think I could finish everything with almost double the time to the fastest sudoku solvers.

Looking at the list we have 22 puzzles in all ... that amounts to roughly less than 6 minutes per puzzle. I dont think more than 3 people will be able to complete all the puzzles....

Rishi

Yeah, that's what I was thinking too, but then I don't really get the idea behind the point reduction, I guess. Because why would it be better to solve a 90 point puzzle at the 60 minute mark than at the 90 minute mark, if the test isn't designed to be finished at the 70 minute mark for the fastest solvers. That's basically why I was wondering.

Edited by Para 2011-07-14 3:20 AM

I can only speculate why this particular point structure has been chosen, but I like it. I have always believed Sudoku to be a "Single Persons Chess" where just solving is not important but strategising too. In this point structure, it would be foolish to tackle puzzles in order of appearance. A little bit of strategy would be needed as to how and in which order the puzzles would be attacked.

can any body help out for how to start the "crossnumber sudoku and number 5 still alive"?
not getting a start.

For the crossnumber sudoku, you basically just have to place all numbers in the grid first. The most obvious point to start, is the left bottom corner. The left bottom vertical number, you can relatively easily prove that only 5876 is possible there, considering the numbers that can cross and the fact no digits can repeat within nonet 7. Once you have that, you should be able to fill ou the whole crossword.

Number 5 still alive I haven't figured out yet myself.



I don't really agree but I guess that's not a discussion to have here.

I mainly was just inquiring with what solving time this test was intended for the fastest solvers (as that is normally what the test length is for), to get an idea on the difficulty and thus how to approach this test. Because I was under the impression that the time extension/point reduction system was intended so that the people who finish just behind the fastest solvers can also finish all puzzles in competition for once, just for less points. Would still appreciate an answer from someone who knows for sure.

thanks para.
actually i forget considering a sudoku rule. i considered it as solving like a crossword puzzle with few guesses but forgotten the basic rule. now i will give it another strike.
"just one cell sudoku"- how to go about it. i could just get few things in the top right corner 3 x 3. but not able to get that answer '2' . can anybody give the explanation for it.

Just one cell sudoku:
R469C7 is a hidden triple {135}. Now R1C7 is a hidden single 2. Or you could do R28C7 is a naked pair {79} for C7, now R1C7 is a naked single 2.

The Number 5 Still Alive example from WSC2 was notoriously difficult and much much much more difficult than the competition puzzle was. This, in my experience, is often the case with Vlad Portugalov puzzles where the "example" is too hard to solve. After 15 minutes, I can explain how to get just 9 sure digits and 2 labeled pairs.

My hope is that someone can give you a link to another Number 5 Still Alive type puzzle from a previous mock test. I can only quickly find the related Number X is Alive puzzle from the May Sudoku test at the moment.