The New Sudoku Players' Forum

by **Bigtone53** » Fri Nov 18, 2005 5:55 pm

It has been mentioned elsewhere but for those in the London UK area, the Friday METROdoku puzzle in the free METRO paper is at least of the same standard as the Sunday Times Superior, bulging with X-wings etc. The rest of the week is rubbish.

by **Crazy Girl** » Sun Nov 20, 2005 11:43 pm

maybe someone with a copy of last friday's METROdoku could post the puzzle, to see how the puzzle compares to Times Superiors :!:

by **Bigtone53** » Mon Nov 21, 2005 4:34 pm

maybe someone with a copy of last friday's METROdoku could post the puzzle, to see how the puzzle compares to Times Superiors

Sorry, but I don't know how to make it look pretty

- - 7 2 - - - - 5
5 - - - 7 9 - 3 -
- 3 - - - - 8 - -
- - 3 - - - - - 1
- - 8 9 - 4 5 - -
1 - - - - - 2 - -
- - 2 - - - - 5 -
- 1 - 6 2 - - - 8
4 - - - - 7 6 - -

by **MCC** » Mon Nov 21, 2005 5:16 pm

It's not bad as it stands, but you highlight the text and click 'code'.

Code: Select all: - - 7 2 - - - - 5 5 - - - 7 9 - 3 - - 3 - - - - 8 - - - - 3 - - - - - 1 - - 8 9 - 4 5 - - 1 - - - - - 2 - - - - 2 - - - - 5 - - 1 - 6 2 - - - 8 4 - - - - 7 6 - -

Or you can do this:

Code: Select all: - - 7| 2 - -| - - 5 5 - -| - 7 9| - 3 - - 3 -| - - -| 8 - - -------------------- - - 3| - - -| - - 1 - - 8| 9 - 4| 5 - - 1 - -| - - -| 2 - - -------------------- - - 2| - - -| - 5 - - 1 -| 6 2 -| - - 8 4 - -| - - 7| 6 - -

by **Bigtone53** » Mon Nov 21, 2005 5:26 pm

Thanks, MCC

by **Pat** » Thu Nov 24, 2005 1:02 pm

chrisr (2005.Oct.24) wrote:there is a free newspaper called The Metro
which I pick up on the London trains every weekday.
And while Monday-Thursday puzzles are little more than handwriting excercises,
the Friday ones for the last 3 weeks have proved much more interesting.

Bigtone53 wrote:It has been mentioned elsewhere but for those in the London UK area, the Friday METROdoku puzzle in the free METRO paper is at least of the same standard as the Sunday Times Superior, bulging with X-wings etc. The rest of the week is rubbish.

The Metro, 2005.Nov.18 (Friday):
Code: Select all
. . 7 | 2 . . | . . 5 5 . . | . 7 9 | . 3 . . 3 . | . . . | 8 . . -------+-------+------ . . 3 | . . . | . . 1 . . 8 | 9 . 4 | 5 . . 1 . . | . . . | 2 . . -------+-------+------ . . 2 | . . . | . 5 . . 1 . | 6 2 . | . . 8 4 . . | . . 7 | 6 . .

many thanks, Bigtone53,
a worthy puzzle indeed!!

while i did solve it without any X-wing,
i'd expect Pappocom to rate it as Very Hard.

- Pat

by **Bigtone53** » Fri Nov 25, 2005 11:56 pm

while i did solve it without any X-wing,
i'd expect Pappocom to rate it as Very Hard.

Today was a bit easier, but I left it at work. I can try and post it with my new found code skills next on Monday if anyone is interested.

by **Hud** » Sat Nov 26, 2005 1:21 am

I copied it to the Pappocom format and it accepted it. I thought I was really losing my touch til a couple magic clues appeared. No X-Y wings either and I don't recall any X wings. It was around my limited limit though. I think old 3x3 would have liked it.

by **vvill** » Fri Dec 02, 2005 1:48 am

Yeah I noticed there's the odd Metro puzzle which is much much harder than their normal standard. Is the hard-on-a-Friday thing some sort of a standard for Sudoku publishing? The local paper where I am now publishes Hard Pappocoms on Friday, otherwise they're always medium or easy.

by **Bigtone53** » Fri Dec 09, 2005 5:30 pm

the Metro Puzzles on Friday continue to exercise the mind. Here is today's if anyone wants to try it. I got there in the end.

Code: Select all: . . . |7 . . |5 . . 4 . . |. . . |. . 7 . . 3 |. 8 6 |. . 1 --------------------- . 6 . |. 5 . |. 4 . . . 4 |2 . 7 |3 . . . 3 . |. 9 . |. 2 . --------------------- 5 . . |9 2 . |6 . . 1 . . |. . . |. . 8 . . 6 |. . 8 |. . .

My first attempt at coding.

by **MCC** » Fri Dec 09, 2005 6:04 pm

The pappocom program rates it a valid v.hard.

by **afjt** » Fri Dec 09, 2005 7:10 pm

It didn't seem that hard - no X-wings etc required.

by **Bigtone53** » Sat Dec 10, 2005 5:56 pm

It didn't seem that hard - no X-wings etc required.

True in this case, but typically these do need at least locked quads, which are never completely obvious.

I only mention these as a free interesting puzzle to Londoners on Fridays, to make up for the final disappearance of the old-fashioned Red London Buses yesterday.

by **Abs** » Fri Dec 16, 2005 9:17 pm

This Friday's(16 Dec) tough sudoku:

Code: Select all: - - -|- 9 -|- - 3 - - -|- - 2|9 1 4 - - -|8 - -|6 - - ----------------- - 4 -|7 - 9|- 5 8 - - -|- - -|- - - 7 3 -|1 - 5|- 2 - ----------------- - - 5|- - 3|- - - 1 7 4|6 - -|- - - 9 - -|- 4 -|- - -

I could only put in 6 numbers, can someone tell me what techiques you used(and when) to solve this puzzle.

by **Crazy Girl** » Fri Dec 16, 2005 11:45 pm

Abs wrote:This Friday's(16 Dec) tough sudoku:

Code: Select all
- - -|- 9 -|- - 3 - - -|- - 2|9 1 4 - - -|8 - -|6 - - ----------------- - 4 -|7 - 9|- 5 8 - - -|- - -|- - - 7 3 -|1 - 5|- 2 - ----------------- - - 5|- - 3|- - - 1 7 4|6 - -|- - - 9 - -|- 4 -|- - -

I could only put in 6 numbers, can someone tell me what techiques you used(and when) to solve this puzzle.

Abs,

First some basic steps: ( I suspect you got these, but here they are anyway)
R6C7 = 4 therefore R7C8=4.
R9C3=3
R7C4=9
then notice these Naked singles:
R8C6=8,
R9C8=6,
R3C8=7, which leads to R1C8=8.
then we have the following grid.

Code: Select all: . . . | . 9 . | . 8 3 . . . | . . 2 | 9 1 4 . . . | 8 . . | 6 7 . -------+-------+------ . 4 . | 7 . 9 | . 5 8 . . . | . . . | . . . 7 3 . | 1 . 5 | 4 2 . -------+-------+------ . . 5 | 9 . 3 | . 4 . 1 7 4 | 6 . 8 | . . . 9 . 3 | . 4 . | . 6 .

with candidate grid:

Code: Select all: 2456 1256 1267 | 45 9 67 | 25 8 3 3568 568 678 | 35 67 2 | 9 1 4 2345 1259 129 | 8 135 14 | 6 7 25 --------------------+------------------+---------------- 26 4 126 | 7 236 9 | 13 5 8 2568 125689 12689 | 234 2368 46 | 137 39 1679 7 3 689 | 1 68 5 | 4 2 69 --------------------+------------------+---------------- 268 268 5 | 9 127 3 | 1278 4 127 1 7 4 | 6 25 8 | 235 39 259 9 28 3 | 25 4 17 | 12578 6 1257

You will notice a pair in Box 2 of {6,7}.
Also there is a Hidden Triplet in Row 3 of {1, 3, 4} which allows some eliminations to take place giving you only one cell in Column 5 for a Certain number, ie Hidden Single.

then you have the Grid: (Spoilers Ahead!!!)

Code: Select all: 45 1256 1267 | 45 9 1467 | 25 8 3 358 56 678 | 35 3567 2 | 9 1 4 345 1259 129 | 8 135 14 | 6 7 25 --------------------+------------------+---------------- 26 4 126 | 7 236 9 | 13 5 8 58 12569 12689 | 34 2368 46 | 137 39 1679 7 3 689 | 1 68 5 | 4 2 69 --------------------+------------------+---------------- 26 26 5 | 9 17 3 | 8 4 17 1 7 4 | 6 5 8 | 23 39 29 9 8 3 | 2 4 17 | 157 6 157

You will notice a naked {2,3,9} triple in Row 8, so {2, 3, 9} do not appear elsewhere in box 9.
Also Naked {2,6} pair in Column 1, so {2,6} do not appear elsewhere in Column 1.
Now there is also another Naked Pair in Row 1, so..... :idea:

This is a interesting puzzle, though it doesn't have any X-Wings it is still a hard nut to crack.

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