The New Sudoku Players' Forum

[jungzimm]

I can usually solve medium puzzles from pappocom's software without listing candidates or branching but this one has got me messed up somehow. Could anyone point me one or two steps in the next direction.

Code: Select all

Original puzzle:


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

As Far as I've gotten (not very far)


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



Grateful for any help you can offer,

John

[RW]

Look for number 9 in box 4.

RW

[ravel]

Unfortunately the 9 alone will not help you much.

How i would try to proceed (hope i dont say too much) ?

What can be seen easily:
In box 9 (right bottom 3x3 group) 5 and 9 (both in columns 8 and 9) only can be in r89c7 (row 8, column 7 and row 9,column 7).
In column 3 (both in box 4) 1 and 3 only can go to r19c3.
78 in box 4 (both in column 3) can only go to r5c1 and r6c2, which gives a 26 pair in r45c3.

Nothing helps to find a number.
So i have to count and start with box 3, where only 3 numbers are left:
r1c7 can only be 36, r1c8 either 36, r2c8 only 1, next number.

No other 1's forced by that, but the 36-pair will help to solve the puzzle.

[Crazy Girl]

If you every want to find/learn new basic skills, check out the following websites

http://www.angusj.com/sudoku/hints.php
http://www.sadmansoftware.com/sudoku/techniques.htm
http://www.scanraid.com/BasicStrategies.htm

[Pat]

I can usually solve Medium puzzles from Pappocom's software without listing candidates or branching,
but this one has got me messed up somehow.
Could anyone point me one or two steps in the next direction.

Original puzzle:

Code: Select all

 . 9 . | 4 . 5 | . . .
 5 . . | . . 8 | 7 . .
 . . 8 | 9 1 . | 4 . .
-------+-------+------
 . 1 . | . . . | 8 . 5
 . 4 . | . . . | . 9 .
 3 . 5 | . . . | . 2 .
-------+-------+------
 . . 9 | . 4 1 | 2 . .
 . . 7 | 3 . . | . . 1
 . . . | 7 . 2 | . 8 .

As Far as I've gotten (not very far):

Code: Select all

 . 9 . | 4 . 5 | . . 8
 5 . 4 | . . 8 | 7 . 9
 . . 8 | 9 1 . | 4 5 2
-------+-------+------
 . 1 . | . . . | 8 . 5
 . 4 . | . . . | . 9 .
 3 . 5 | . . . | . 2 .
-------+-------+------
 . . 9 | . 4 1 | 2 . .
 . . 7 | 3 . . | . . 1
 . . . | 7 . 2 | . 8 .

in r2, only one place for the 1;

now the 3 for box3 must be in r1,
so we have a box-line interaction —
in c3, only one place for the 3 (not in r1).

~ Pat

[jungzimm]

Thank you everyone and especailly for the pointers to the advanced techniques. It still took me a while after the 1 in Box 3 and the 59 in r89c7; but eventually I got it. I've still got a ways to go in comprehending the more advanced stuff.