スカイスクレイパー数独
3
5
3
1
4
2
3
2
2
2
3
1
2
3
2
3
3
3
5
1
3
9
8
7
7
2
5
6
7
3
4
5
1
8
7
4
2
6
9
3
8
7
9
5
4
6
7
4
8
5
2
4
3
1
8
5
5
1
5
2
4
2
3
2
3
4
3
2
4
4
2
1
2
4
スカイスクレイパー数独の遊び方
標準数独ルールが適用されます。各青い手がかり数字は、その端からグリッドを見たときに見える数字の数を示します — 数字は、その方向から見て前のすべての数字より大きい場合にのみ見えます。
完全ガイド →
外部ヒントは、その端から見える「建物」の数を示します
スカイスクレイパー数独とは？
スカイスクレイパーナンプレは、各数字をその高さの建物と見なします。グリッドの外側のヒントは、その端から内側を見たときに見える建物の数を示します。より高い建物はその後ろのすべての低い建物を遮ります。1のヒントは最初の建物が9でなければならないことを意味します。9のヒントは、建物が厳密に増加する順序（1,2,3,4,5,6,7,8,9）で配置されていることを意味します。このバリアントは、ナンプレの論理と順列推論の両方を必要とします。
概要
| 制約タイプ | アウトサイドヒント |
| 典型的な初期数字 | 4–10 clue values |
| 難易度評価 | ★★★★☆ 4/5 |
| 平均解答時間 — 簡単 | 12分 |
| 平均解答時間 — ミディアム | 25分 |
| 平均解答時間 — 難しい | 50分 |
| 平均解答時間 — エキスパート | 80分 |
スカイスクレイパー数独 の解き方
| テクニック | それが何をするか | レベル |
|---|---|---|
| Clue 1 Forces 9 First | A visibility clue of 1 means the first building from that edge must be a 9. All shorter buildings behind it are hidden. | 上級 |
| Clue 9 Forces Ascending Order | A clue of 9 means all buildings are visible, so digits are in strictly ascending order from that edge: 1, 2, 3, 4, 5, 6, 7, 8, 9. | 上級 |
| Permutation Enumeration | For each clue value V, enumerate all permutations of 1–9 that give exactly V visible buildings. Cross-reference opposite-edge clues. | 上級 |
| 9 Always Visible | The digit 9 is always visible from either edge. The digit 8 is visible only if it appears before any 9 from that edge. | 上級 |
| Multi-Edge Constraint | Combine the clue from one edge with the opposite edge's clue. Both must be simultaneously satisfiable. | 上級 |
平均解答時間
簡単
12分
ミディアム
25分
難しい
50分
エキスパート
80分
よくある質問
Skyscraper Sudokuとは何ですか？
Skyscraper Sudoku is a variant where numbers appear outside the grid on all four sides. Each number tells you how many distinct 'buildings' (digits) are visible when looking into that row or column from that side. Taller buildings hide shorter ones behind them — a larger digit blocks any smaller digit placed further into the row.
How does visibility work in Skyscraper Sudoku?
Imagine the digits in a row as buildings of different heights. Looking from one end, you can see a building only if no taller building stands between you and it. A clue of 1 means only the first building is visible, so it must be the tallest (digit 9). A clue of 9 means all buildings are visible, so the row must be in ascending order from that side.
What do extreme clue values tell me?
A clue of 1 means the first cell from that side holds a 9 — it blocks everything else. A clue of 9 means the row or column is in strictly ascending order from that direction (1,2,3,4,5,6,7,8,9). Both are immediately actionable. Mid-range clues require enumerating valid permutations.
Is Skyscraper Sudoku harder than regular Sudoku?
Yes, generally. Skyscraper clues require enumerating valid digit permutations for each row and column, which is more combinatorially intensive than classic Sudoku elimination. Easy puzzles are accessible; hard and expert puzzles require tracking visibility across multiple rows and columns simultaneously.
What is the best first strategy for Skyscraper Sudoku?
Start with clues of 1 and 9 — they immediately fix a digit or fully determine the order of a row. Then look for clues of 2, which constrain the position of the 9 significantly. Combine skyscraper deductions with standard Sudoku box and row/column scans.
How long does Skyscraper Sudoku take to solve?
Easy puzzles take 8–20 minutes. Medium puzzles run 20–40 minutes. Hard puzzles average 40–75 minutes and expert puzzles often exceed 90 minutes. Fast solvers develop the ability to enumerate valid visibility permutations quickly without writing them all out.