Pil Sudoku
5
6
7
9
4
6
7
1
2
5
7
5
4
3
7
8
1
4
4
5
8
3
2
6
2
8
5
7
2
5
1
4
3
7
8
9
5
6
Sådan spiller du Arrow Sudoku
Standard Sudoku-regler gælder. Ekstra regel: cifrene langs hver piles hale skal summere til cifferet i cirklen ved pilens base. Cirklen selv er en normal Sudoku-celle — dens værdi bestemmer, hvad pilecellerne skal summere til.
Fuld guide →
Cifre på en pil skal summere til cifferet i cirklen
Hvad er Pil Sudoku?
Arrow Sudoku placerer pile på gitteret, hver startende fra en cirklet celle. Cifrene i alle celler langs pilen (ikke inklusive cirklen) skal summere til det ciffer, der er placeret i den cirklede celle. Da det maksimale ciffer er 9, er lange pile med mange celler stærkt begrænsede. Arrow Sudoku kombinerer ofte smukt med standard eliminations- og kandidatlogik.
På et Blik
| Begrænsningstype | Linjebegrænsninger |
| Typiske givne tal | 20–26 |
| Sværhedsgradsvurdering | ★★★★☆ 4/5 |
| Gns. løsningstid — Let | 12 min |
| Gns. løsningstid — Mellem | 25 min |
| Gns. løsningstid — Svær | 50 min |
| Gns. løsningstid — Ekspert | 80 min |
Sådan løser du Pil Sudoku
| Teknik | Hvad det gør | Niveau |
|---|---|---|
| Arrow Sum Bounding | The circle digit equals the sum of all arrow shaft cells. A 3-cell arrow with circle 5 means the three shaft cells average under 2 — severely constraining options. | Avanceret |
| Max/Min Arrow Analysis | The maximum sum of N cells is 9+8+7+…; the minimum is 1+2+3+…. If the circle digit falls outside these bounds, a constraint error exists. | Avanceret |
| Bifurcation on Short Arrows | For 2-cell arrows with a small circle (e.g., 3), only (1,2) or (2,1) works — enumerate cases to find forced placements quickly. | Avanceret |
| Arrow–Region Interaction | Arrow cells sharing a box or row with the circle create indirect constraints — combine the sum equation with standard Sudoku uniqueness. | Avanceret |
| Repeating Digits on Arrows | Arrow shaft cells can repeat digits (unlike Killer cages). Factor this in when enumerating possible sums. | Avanceret |
Gennemsnitlige Løsningstider
Let
12 min
Mellem
25 min
Svær
50 min
Ekspert
80 min
Ofte stillede spørgsmål
Hvad er Arrow Sudoku?
Arrow Sudoku is a variant where arrows are drawn across the grid. Every digit placed along an arrow must sum to the number written inside the circle at the arrow's base. Standard Sudoku rules still apply — every row, column, and 3×3 box must contain the digits 1–9 exactly once.
How do the arrows and circles work?
Each arrow starts at a circle and extends through one or more cells. The digit in the circle is the target sum for all cells the arrow passes through. A single-cell arrow tells you the exact digit in that cell. Longer arrows have multiple possible combinations, which you narrow down using Sudoku constraints.
Is Arrow Sudoku harder than regular Sudoku?
It depends on your experience. Arrow Sudoku adds an arithmetic layer on top of standard logic. Easy puzzles are comparable in difficulty to medium classic Sudoku. Hard and expert arrow puzzles require simultaneous constraint-tracking that most players find significantly more challenging than any classic Sudoku difficulty.
Can a digit repeat along an arrow?
No — digits can repeat on an arrow only if standard Sudoku rules allow it. Because each row, column, and box must contain 1–9 once, a digit can appear twice on an arrow only if the two cells are in different rows, columns, and boxes. In practice, most arrow cells are highly constrained.
What is the best first move in Arrow Sudoku?
Start with single-cell arrows — the digit in that cell equals the circle value directly. Then look for short arrows with extreme sums. A 2-cell arrow summing to 3 can only be {1,2}; summing to 17 can only be {8,9}. These give you the tightest starting constraints without any guessing.
How long does Arrow Sudoku take to solve?
Easy puzzles take 5–15 minutes. Medium puzzles typically run 15–30 minutes. Hard puzzles average 30–60 minutes, and expert puzzles can take over an hour even for experienced solvers. Solve times improve quickly once you develop intuition for which arrow combinations are possible at a glance.