# Sudoku naked single

Hidden Single means that for a given digit and house only one cell is left to place that digit. Red hot lauren nude. I did not list all the cells and I made up the numbers. The small red digits are the candidate sets. Naked Single Naked Single means that in a specific cell only one digit remains possible the last remaining candidate has no other candidates to hide behind and is thus naked.

Naked quads are rare, but they can occur. Sudoku naked single. Example on the left: Hidden and Naked Singles are not so easy to spot. If there is only 1 cell of the 3 where the digit may be placed, then we should have caught that with cross-hatching. All cells in that block are "blocked" by a placed digit 3, r6c4 is the last possible cell for digit 3 in block 5.

Suppose we have a hidden pair and we try to place one of the extra candidates in one of the empty cells of the pair. If a candidate digit is limited in a row to only cells in one of the blocks the row intersects, then that digit may be eliminated as a candidate from all cells in the block that are not in the row.

Hence only the candidates of the hidden pair may be placed in the empty cells of the pair and all other candidates can be eliminated from the pair. A little reflection on the definition and discussion of naked tuples in the previous paragraph should convince you that this assertion must be true for all puzzles with a solution.

I took Doc Brown's suggestion to add 1 to C to make it a little more interesting. Brande roderick nude sex. If a set of N empty cells has less than N candidates the puzzle is unsolvable because there are not enough candidates to populate all the empty cells.

I'll leave the original intact and then point out the flaw. Now is a good time to point out the result of tuples analysis. If a square that is not part of the naked pair were set to 2, for example, then both of the squares in the naked pair would have 3 as the only candidate, which would be invalid.

In other words, a missing digit scan is looking for empty cells with only one candidate. Once again it's an '8', because its buddy cells contain every digit from '1' through '9', except for '8'. As with hidden pairs, a hidden triple allows you to eliminate the extra candidates from the empty cells of the triple. It flows logically and naturally from the rules of Sudoku itself. I cut it down too much here. Hence, the candidates of a naked pair can only be placed in the empty cells of the pair and may be eliminated from all other empty cells in the region.

Analysis techniques identify where a digit cannot go, that is, it eliminates a digit from the candidates set s of one or more cells. Can you solve it? So let's keep a note of this on the side. Sexy dating games for girls. You can remove them from the graph. DocBrown While I'm not seeing a rebuttal off the top of my head it must exist--otherwise there would be no reason to look for hidden sets as they would always be revealed by finding the naked sets.

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The right side shows a Locked Pair in row 8 and block 8 eliminating 18 candidates. I am writing a sudoku solver in scheme. Lady with the biggest tits. I'll leave the original intact and then point out the flaw.

A 4 must be placed here, because it cannot be placed in any other cell in the block. However, sometimes the numbers of the triple don't all appear in all three squares, as in the example below. Again the proof is simple and as before proceeds by contradiction. Questions Tags Users Badges Unanswered. Sudoku naked single. Have you tried a brute force approach?

When we examine the block in the center of the bottom band, we see that there is only one green cell in it. Granted, this will be used in a sudoku solver, but I'm asking about the general problem. Best hot nude girls. Thinking one step further: Sudoku Tutorials Blog Bookmark.

So let's keep a note of this on the side. If a digit must appear in at least one cell of the set then that digit can be eliminated from the candidate sets of all the common buddies of the set. You can think of it as a pair and its complimentary quad with the quad breaking down into a pair of complimentary pairs. Can you solve it? Thus the naive brute force is only combinations to check. Feel free to ask for any specific part, or even the whole code.

With the added benefit that the method finds even quads and bigger sets. Cedric Mamo 4. One of the squares in the pair has to be 2, and one of the squares in the pair has to be 3. Jessie graff nude. So, in either case the result is to partition the empty cells of the region into 2 naked tuples. The small digits are the candidate sets and the digits shown in blue are the candidates eliminated by the hidden pair.

But I feel you might prefer to create most of this code yourself. Draw lines through all rows and columns that already have an instance of that digit set in your mind only please.

In the discussion that follows all references to tuples exclude the trivial tuple unless otherwise noted. The candidates 1, 2 and 4 form the triple because they only appear in the cells of the triple and not in any of the other empty cells in the 5 th column.

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If you discover a naked tuple, after eliminating the tuple candidates from the non-tuple cells, the complimentary tuple is stripped bare naked. Spainish girls nude. Hence only the candidates of the hidden pair may be placed in the empty cells of the pair and all other candidates can be eliminated from the pair.

Every region with one or more empty cells has a trivial naked tuple. Be aware that you need to make copies of your board in pass 2 where the copy shares no structure with the original.

How best to Implement naked single and hidden single in scheme Ask Question. Let's examine the possible values of R5 C8 - these are called candidates. Sudoku naked single. Consider a region with N empty cells. Analysis techniques identify where a digit cannot go, that is, it eliminates a digit from the candidates set s of one or more cells. If no other cells are found containing them then I have found a match. Now we are down to 6, for a total of 64 cases.

When there are exactly N candidates for N cells, then none of those candidates can be placed in a cell outside the set, because doing so would reduce the number of candidates for the set to less than N and the puzzle would be unsolvable.

How to find them Finding Naked Subsets is best done, when all remaining candidates have been penciled in. Naked Subsets are similar to Hidden Subsets, the only difference is that it is not about candidates being confined to cells as in Hidden Subsetsbut about cells containing only a certain number of candidates. Naked triples are harder to spot.