Express DC Hard

All about puzzles in newspapers, magazines, and books

Express DC Hard

Postby Zonkerbl » Fri Dec 21, 2007 10:52 pm

_____________
|__4|___|527|
|___|__2|461|
|2_1|74_|389|
|------------
|__9|12_|__8|
|_2_|___|_1_|
|61_|_98|2__|
|------------
|__5|__4|1_2|
|172|5__|___|
|__6|2__|8__|
|------------

Hm, hope this comes out... Haven't quite figured out the whole formatting thing. Anyway I've been scratching away at this off and on and was wondering what the next step might be... Thanx.
Zonkerbl
 
Posts: 7
Joined: 21 December 2007

Postby tarek » Fri Dec 21, 2007 11:22 pm

where would you place a 9 in row 5?
where would you place an 8 in row 8?

tarek
User avatar
tarek
 
Posts: 2574
Joined: 05 January 2006

Postby Zonkerbl » Sat Dec 22, 2007 12:01 am

AAAAAARGH!

Didn't even notice that.

Doh.

Thanks!
Zonkerbl
 
Posts: 7
Joined: 21 December 2007

Re: Express DC Hard

Postby Cec » Sat Dec 22, 2007 9:55 am

Zonkerbl wrote:"...Hm, hope this comes out... Haven't quite figured out the whole formatting thing..."

Hi Zonkerbl,
The instructions for posting puzzles are set out in the "Sticky" thread at the top of this forum and you can read about them by clicking on HERE

This Thread might also help you.

Cec
Cec
 
Posts: 1039
Joined: 16 June 2005

Postby Zonkerbl » Sat Dec 22, 2007 2:49 pm

*experiments*
Code: Select all
_____________
|__4|___|527|
|___|__2|461|
|2_1|74_|389|
|------------
|__9|12_|__8|
|_2_|___|_1_|
|61_|_98|2__|
|------------
|__5|__4|1_2|
|172|5__|___|
|__6|2__|8__|
|------------


Aha! Ok, I didn't get the
Code: Select all
bit.
Zonkerbl
 
Posts: 7
Joined: 21 December 2007

Express DC Hard

Postby Cec » Sun Dec 23, 2007 9:40 am

Hi again Zonkerbl,

I suspect your problem is an incorrectly prepared "template" grid and not the code button. The blank grid must show a "full stop" mark for each cell as seen in my above Thread and NOT a continuous single line for blank cells which appears on your posted grid.

Using the top row of your puzzle as an example then the row will look untidy like this if you type a full line for blank cells:
Code: Select all
|___ 4|____|5 2 7|
 

or neat and tidy like this if you type a "full stop" mark for a blank cell:
Code: Select all
|. . 4|. . .|5 2 7|

and, of course, even better like this, for the whole puzzle:
Code: Select all
 *-------------------*
 |. . 4 |. . . |5 2 7|
 |. . . |. . 2 |4 6 1|
 |2 . 1 |7 4 . |3 8 9|
 |------|------|-----|
 |. . 9 |1 2 . |. . 8|
 |. 2 . |. . . |. 1 .|
 |6 1 . |. 9 8 |2 . .|
 |------|------|-----|
 |. . 5 |. . 4 |1 . 2|
 |1 7 2 |5 . . |. . .|
 |. . 6 |2 . . |8 . .|
 *-------------------*


I hope this helps,

Cec
Cec
 
Posts: 1039
Joined: 16 June 2005

Re: Express DC Hard

Postby Zonkerbl » Sat Jan 19, 2008 6:23 am

Ok, I have another problem from the express, let me try out my coding skills:
Code: Select all
 *-------------------*
 |. 7 . |1 . . |. 5 .|
 |4 5 1 |. . . |. 3 .|
 |. . . |4 5 . |7 . 1|
 |------|------|-----|
 |. . 7 |9 . 5 |. 4 3|
 |5 . . |8 . 4 |. . 9|
 |9 4 . |. . 6 |5 . .|
 |------|------|-----|
 |7 . 2 |. 4 . |. . 5|
 |. 9 4 |5 . . |8 . 6|
 |. . 5 |. . 9 |. . .|
 *-------------------*
Zonkerbl
 
Posts: 7
Joined: 21 December 2007

Re: Express DC Hard

Postby daj95376 » Sat Jan 19, 2008 7:47 am

Zonkerbl wrote:Ok, I have another problem from the express, let me try out my coding skills:

Your coding skills worked great.

Now, look at <8> in [row 5] & [column 7] and see how it affects [box 6] and, eventually, [r6c3].

There's also <1> in [box 5], but it's not necessary.
daj95376
2014 Supporter
 
Posts: 2624
Joined: 15 May 2006

Postby Zonkerbl » Sat Jan 19, 2008 4:01 pm

Ah, there we go, and from there it's easy.

I was looking for stuff like that but that one slipped by me...

Thanks!
Zonkerbl
 
Posts: 7
Joined: 21 December 2007

Re: Express DC Hard

Postby Cec » Sun Jan 20, 2008 2:03 am

daj95376 wrote:".....Now, look at <8> in [row 5] & [column 7] and see how it affects [box 6] and, eventually, [r6c3]..."

In box6 I can see that digit 8 cannot go in r5 or in c7 but how do you determine where the 8 goes in the only two remaining cells r6c8 or r6c9.

On another matter which I've been reluctant to query but now wish to do so, I understand that <8> signifies digit 8. I'm not a mathematician but my recollection at school was that "<" meant "less than" and ">" meant "more than". Would it not be clearer to sudoku forum members to define digit 8 as simply digit 8 rather than <8>?

Cec
Cec
 
Posts: 1039
Joined: 16 June 2005

Re: Express DC Hard

Postby daj95376 » Sun Jan 20, 2008 4:06 am

Cec wrote:
daj95376 wrote:".....Now, look at <8> in [row 5] & [column 7] and see how it affects [box 6] and, eventually, [r6c3]..."

In box6 I can see that digit 8 cannot go in r5 or in c7 but how do you determine where the 8 goes in the only two remaining cells r6c8 or r6c9.

You don't initially determine where 8 goes in [r6c89]. That's why I included the and, eventually ... to indicate that 8 is eliminated in [r6c3] because it must be in [r6c89].

Cec wrote:On another matter which I've been reluctant to query but now wish to do so, I understand that <8> signifies digit 8. I'm not a mathematician but my recollection at school was that "<" meant "less than" and ">" meant "more than". Would it not be clearer to sudoku forum members to define digit 8 as simply digit 8 rather than <8>?

I don't have any idea when or specifically why I started placing inequality signs around digits. I suspect that it was to give them a distinctive appearance -- like my habit of using [r6c89], as used in chains, instead of r6c89, as used in sentences.

Sudoku members have no problem understanding that Naked Pair 23 is about the digits 2 & 3 and not the number twenty-three. It should probably be written Naked Pair {2,3}. I don't see it happening ... for clarity or any other reason.

It would be more accurate for me to use {8} if I'm going to enclose the digit 8. For clarity, I will try to drop the inequality signs and just use digits.
daj95376
2014 Supporter
 
Posts: 2624
Joined: 15 May 2006

Re: Express DC Hard

Postby Cec » Sun Jan 20, 2008 5:41 am

daj95376 wrote:"... That's why I included the and, eventually ... to indicate that 8 is eliminated in [r6c3] because it must be in [r6c89]...."

Thanks daj95376 for your prompt reply. I incorrectly assumed that the above puzzle could be solved without reference to pencilmarks which are not shown in the above grid.

daj95376 wrote:"... Sudoku members have no problem understanding that Naked Pair 23 is about the digits 2 & 3 and not the number twenty-three. For clarity, it should probably be written Naked Pair {2,3}. I don't see it happening

It would be more accurate for me to use {8} if I'm going to enclose the digit 8. For clarity, I will try to drop the inequality signs and just use digits."

I think the forum members' acceptance of "Naked Pair 23" or, as I prefer "Naked Pair [23]", is because of actually quoting the two words viz. "Naked Pair" to describe this particular "hint". I couldn't envisage members inferring {23} to mean number 23 because 9 is the maximum number used in a puzzle.

Because digits 1 to 9 are single numbers the practice of enclosing single digits between brackets seemed unnecessary to me, hence my preference to define a digit as simply digit 8 . Your intention to drop the inequality signs and just use digits is noted .

Cec
Cec
 
Posts: 1039
Joined: 16 June 2005

Postby daj95376 » Sun Jan 20, 2008 8:02 am

Yes, my 23 example stunk. What I was trying to say and what resulted after several edits were not the same. Although there are examples where people don't use the same notation, I should try to follow the ones that are most commonly observed. However, don't expect me to give up placing [] around cells and units in sentences. Regards!
daj95376
2014 Supporter
 
Posts: 2624
Joined: 15 May 2006

Express DC hard

Postby Cec » Sun Jan 20, 2008 9:57 am

daj95376 wrote:Yes, my 23 example stunk............. However, don't expect me to give up placing [] around cells and units in sentences. Regards!

I appreciate your candid reply daj95376. I too find it difficult at times to put my thinking into words as two different meanings can often result - hence my previous reluctance to air my thoughts on this matter.

I see nothing wrong in your continuing to place [] around cells and units and, in fact, I do this myself at times to better explain/identify the situations you have mentioned. My concern was the use of <> when referring to digits which I believe can confuse newcomers. It seems we both agree that either digit 8 or [8] would be preferable. Regards and thanks again.

Cec
Cec
 
Posts: 1039
Joined: 16 June 2005


Return to Published puzzles