XV Sudoku
5
9
3
4
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5
1
7
9
4
7
4
3
6
2
5
8
6
3
5
7
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4
8
7
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9
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7
2
8
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1
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9
2
8
Cara bermain XV Sudoku
Peraturan Sudoku standard terpakai. X antara dua sel bersebelahan bermaksud mereka berjumlah 10. V bermaksud mereka berjumlah 5. Pasangan tanpa penanda dijamin tidak berjumlah 10 atau 5.
Panduan penuh →
X antara sel bermaksud jumlahnya 10; V bermaksud jumlahnya 5
Apakah XV Sudoku?
XV Sudoku (juga dipanggil Sudoku Sepuluh-Lima) meletakkan penanda X dan V di antara sel bersebelahan. X bermaksud dua sel tersebut berjumlah 10; V bermaksud jumlahnya 5. Banyak teka-teki XV menggunakan kekangan negatif: ketiadaan penanda menjamin pasangan itu tidak berjumlah 10 mahupun 5. Digabungkan dengan Sudoku standard, ini memberikan kekangan yang sangat ketat merentasi grid.
Sekilas Pandang
| Jenis kekangan | Hubungan Petak |
| Biasa diberi | 18–24 |
| Penilaian kesukaran | ★★★☆☆ 3/5 |
| Purata masa selesaikan — Mudah | 8 min |
| Purata masa selesaikan — Sederhana | 18 min |
| Purata masa selesaikan — Sukar | 35 min |
| Purata masa selesaikan — Pakar | 62 min |
Cara Menyelesaikan XV Sudoku
| Teknik | Apa yang dilakukannya | Tahap |
|---|---|---|
| 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. | Lanjutan |
| 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. | Lanjutan |
| Marker Chain Logic | Multiple consecutive X and V markers in a row form a sum chain — enumerate valid assignments for the entire chain simultaneously. | Lanjutan |
| Box X-Interaction | An X pair forces both digits into specific positions within their shared box, constraining all remaining cells of that box. | Lanjutan |
Purata Masa Selesaikan
Mudah
8 min
Sederhana
18 min
Sukar
35 min
Pakar
62 min
Soalan Lazim
Apakah 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.