- Code: Select all
*-----------------------------------------------------------*
| 4 18 7 | 58 6 15 | 3 2 9 |
| 6 28 9 | 78+2 37+28 23 | 4 5 1 |
| 5 12 3 | 4 12 9 | 6 8 7 |
|-------------------+-------------------+-------------------|
| 7 9 5 | 6 13 13 | 2 4 8 |
| 8 4 6 | 57+2 27 25 | 9 1 3 |
| 1 3 2 | 9 4 8 | 5 7 6 |
|-------------------+-------------------+-------------------|
| 9 6 4 | 1 5 7 | 8 3 2 |
| 3 5 1 | 2+8 8+2 6 | 7 9 4 |
| 2 7 8 | 3 9 4 | 1 6 5 |
*-----------------------------------------------------------*
sweetbix wrote:Am I right that when you have many poly valued cells you have to set up the BUG grid and then make implications ( e.g. by chains) from all the non-BUG candidates? There isn't one simple application as tso described for a single poly value cell.
Making implications from all non-BUG candidates is just one way to go. In this particular case, it's much easier to see that the grid reduces to a BUG+1 when a 2 is placed in r8c4 or an 8 is placed in r8c5; therefore these placements are valid. BTW, a grid with one single poly-valued cell is called a BUG+1.
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+-----------------+------------------+----------------+
| 69 35 49 | 56+49 1 2 | 34 7 8 |
| 26+9 38 28+49 | 69+4 7 49 | 34 5 1 |
| 7 45 1 | 3 8 45 | 2 9 6 |
+-----------------+------------------+----------------+
| 8 6 59 | 7 23 35 | 1 4 29 |
| 4 2 7 | 8 9 1 | 6 3 5 |
| 59 1 3 | 45+2 24 6 | 7 8 29 |
+-----------------+------------------+----------------+
| 3 9 6 | 1 5 7 | 8 2 4 |
| 25 7 45+2 | 24 6 8 | 9 1 3 |
| 1 48 28+4 | 29+4 34+2 39+4 | 5 6 7 |
+-----------------+------------------+----------------+
sweetbix wrote:If its simple to explain can you tell me how in this example from the BUG thread you know that the 9 is a non-BUG in r1c4 and a BUG in r2c4. Is it related to the number of poly valued cells there are with that candidate?
To set a BUG grid, you should always start from a unit with a single poly-valued cell. For this particular grid, the starting cell is r9c6 and the sequence after that is:
R9C6=<39>, R9C5=<34>, R9C4=<29>, R9C3=<28>, R8C3=<45>, R6C4=<45>, R2C3=<28>, R2C1=<26>, R1C4=<56>, R2C4=<69>.
As it turned out, the 9 is a non-BUG candidate in r1c4 and a BUG candidate in r2c4.