XV Sudoku
5
9
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5
1
7
9
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6
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5
8
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3
5
7
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4
8
7
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9
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7
2
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1
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9
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8
Hur man spelar XV Sudoku
Standard Sudoku-regler gäller. X mellan två intilliggande celler betyder att de summerar till 10. V betyder att de summerar till 5. Par utan markör garanteras inte summera till 10 eller 5.
Fullständig guide →
X mellan celler betyder att de summerar till 10; V betyder att de summerar till 5
Vad är XV Sudoku?
XV Sudoku (även kallat Ten-Five Sudoku) placerar X- och V-markörer mellan angränsande celler. Ett X betyder att de två cellerna summerar till 10; ett V betyder att de summerar till 5. Många XV-pussel använder den negativa begränsningen: frånvaron av en markör garanterar att paret varken summerar till 10 eller 5. I kombination med standard Sudoku ger detta mycket snäva begränsningar över hela rutnätet.
Översikt
| Begränsningstyp | Cellrelationer |
| Typiska givna | 18–24 |
| Svårighetsbetyg | ★★★☆☆ 3/5 |
| Genomsnittlig lösningstid — Lätt | 8 min |
| Genomsnittlig lösningstid — Medel | 18 min |
| Genomsnittlig lösningstid — Svår | 35 min |
| Genomsnittlig lösningstid — Expert | 62 min |
Hur man löser XV Sudoku
| Teknik | Vad den gör | Nivå |
|---|---|---|
| Negative Constraint | Where no X or V appears between adjacent cells, their sum is neither 10 nor 5. This eliminates (1,9), (2,8), (3,7), (4,6) for X and (1,4), (2,3) for V. | Avancerad |
| Sum Pair Enumeration | List all digit pairs that sum to 10 (for X) or 5 (for V), then use row/column placement to identify which pair must occupy each marked pair. | Avancerad |
| Marker Chain Logic | Multiple consecutive X and V markers in a row form a sum chain — enumerate valid assignments for the entire chain simultaneously. | Avancerad |
| Box X-Interaction | An X pair forces both digits into specific positions within their shared box, constraining all remaining cells of that box. | Avancerad |
Genomsnittliga lösningstider
Lätt
8 min
Medel
18 min
Svår
35 min
Expert
62 min
Vanliga frågor
Vad är XV Sudoku?
XV Sudoku is a variant where X and V symbols appear between adjacent cells. An X marks two cells that sum to 10. A V marks two cells that sum to 5. Standard Sudoku rules apply, and — critically — all X and V relationships are fully marked: if there is no symbol between two adjacent cells, those cells are guaranteed not to sum to either 10 or 5.
What pairs sum to 10 (X)?
The valid X pairs are: 1&9, 2&8, 3&7, 4&6. Note that 5&5 sums to 10 but standard Sudoku uniqueness rules prevent two 5s from being adjacent in most cases. The X constraint immediately limits each marked cell to a small set of candidates.
What pairs sum to 5 (V)?
The valid V pairs are: 1&4, 2&3. Only four digits can ever appear in a V cell: 1, 2, 3, or 4. This makes V markers particularly powerful for restricting candidates in the lower half of the digit range.
How does the no-symbol constraint work?
All X and V relationships are shown — if two adjacent cells have no symbol, their sum is guaranteed to be neither 5 nor 10. This negative constraint eliminates candidate pairs from unmarked cell boundaries and is often as useful as the explicit symbols.
Is XV Sudoku hard to learn?
The rules are simple to memorise. The challenge is applying both the positive (X, V) and negative (no symbol) constraints simultaneously across the entire grid. Easy puzzles are very accessible; expert puzzles require exhaustive tracking of all adjacent-cell relationships.
How long does XV Sudoku take to solve?
Easy puzzles take 8–15 minutes. Medium puzzles run 15–30 minutes. Hard puzzles average 30–60 minutes and expert puzzles often exceed 90 minutes. The no-symbol negative constraint is the most time-consuming to apply systematically across a densely marked grid.