XV Sudoku
5
9
3
4
3
2
5
1
7
9
4
7
4
3
6
2
5
8
6
3
5
7
4
4
8
7
3
9
3
7
2
8
6
1
3
9
2
8
Errori
0/3
Punteggio
-
Tempo
00:00
Progresso0%
Facile · XV Sudoku
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Come giocare a XV Sudoku
Si applicano le regole standard del Sudoku. X tra due celle adiacenti significa che sommate danno 10. V significa che sommate danno 5. Le coppie senza indicatore sono garantite non sommare a 10 o 5.
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X tra le celle significa che sommate danno 10; V significa che sommate danno 5
XV Sudoku Facile
XV Sudoku Medio
XV Sudoku Difficile
XV Sudoku Esperto
Cos'è XV Sudoku?
XV Sudoku (chiamato anche Ten-Five Sudoku) posiziona marcatori X e V tra celle adiacenti. Una X significa che le due celle sommate danno 10; una V significa che sommate danno 5. Molti puzzle XV usano il vincolo negativo: l'assenza di un marcatore garantisce che la coppia non sommi né a 10 né a 5. Combinato con il Sudoku standard, questo fornisce vincoli molto stretti su tutta la griglia.
A Colpo d'Occhio
| Tipo di vincolo | Relazioni tra Celle |
| Dati tipici | 18–24 |
| Valutazione della difficoltà | ★★★☆☆ 3/5 |
| Tempo medio di risoluzione — Facile | 8 min |
| Tempo medio di risoluzione — Medio | 18 min |
| Tempo medio di risoluzione — Difficile | 35 min |
| Tempo medio di risoluzione — Esperto | 62 min |
Come Risolvere XV Sudoku
| Tecnica | Cosa fa | Livello |
|---|---|---|
| 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. | Avanzato |
| 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. | Avanzato |
| Marker Chain Logic | Multiple consecutive X and V markers in a row form a sum chain — enumerate valid assignments for the entire chain simultaneously. | Avanzato |
| Box X-Interaction | An X pair forces both digits into specific positions within their shared box, constraining all remaining cells of that box. | Avanzato |
Tempi Medi di Risoluzione
Facile
8 min
Medio
18 min
Difficile
35 min
Esperto
62 min
Domande Frequenti
Cos'è l'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.