Passi risolutivi (41)
Passo 1
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 4 in G3 changed to solution
Passo 2
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 6 in H3 changed to solution
Passo 3
Hidden Singles
valore: 5.1
categoria doc: Getting_Started
3 in B8 is last in column/box
3 in E4 is last in column
3 in G5 is last in row/box
7 in C4 is last in row/box
7 in E9 is last in row/column/box
7 in H2 is last in column/box
Passo 4
Hidden Singles
valore: 4.7
categoria doc: Getting_Started
7 in J6 is last in row/column/box
Passo 5
Naked Pair
valore: 23.1
categoria doc: Naked_Candidates
Naked Pair 4/6 on cells {A5|E5} means
- 4/6 can be removed from C5
Passo 6
Hidden Pair
valore: 44.8
categoria doc: Hidden_Candidates
Hidden Pair 3/8 in Box 1, on cells {A1|A2}
- removes 1/4/6 from A1
- removes 4/6 from A2
Passo 7
Pointing Pairs
valore: 66.4
categoria doc: Intersection_Removal
Pair: between Box 1 and Row C:
- 1 can be removed from C7
- 1 can be removed from C8
Passo 8
Pointing Pairs
valore: 66
categoria doc: Intersection_Removal
Pair: between Box 2 and Row A:
- 2 can be removed from A9
Passo 9
Pointing Pairs
valore: 65.2
categoria doc: Intersection_Removal
Pair: between Box 5 and Col 6:
- 8 can be removed from G6
- 8 can be removed from H6
Last candidate 2 in G6 changed to solution
Passo 10
Hidden Singles
valore: 4.1
categoria doc: Getting_Started
2 in A4 is last in row/column/box
Passo 11
Hidden Pair
valore: 39.1
categoria doc: Hidden_Candidates
Hidden Pair 2/9 in Col 9, on cells {F9|J9}
- removes 1/4/6 from F9
- removes 5/6 from J9
Passo 12
Hidden Singles
valore: 3.8
categoria doc: Getting_Started
6 in J8 is last in row/box
Passo 13
Pointing Pairs
valore: 54.1
categoria doc: Intersection_Removal
Pair: between Box 7 and Col 1:
- 2 can be removed from E1
- 2 can be removed from F1
Passo 14
Line/Unit Reduction
valore: 69.9
categoria doc: Intersection_Removal
Line/Box Reduction: 6s in box 4 remove the following in the same box:
- 6 can be removed from D1
- 6 can be removed from D2
- 6 can be removed from E1
- 6 can be removed from E2
Passo 15
Rectangle Elimination
valore: 86.7
categoria doc: Rectangle_Elimination
If +1[E6] then -1[E7] forcing +1[B7] which removes all 1s from Box 2, so E6 cannot be 1
Passo 16
Rectangle Elimination
valore: 86
categoria doc: Rectangle_Elimination
If +6[A9] then -6[A5] forcing +6[E5] which removes all 6s from Box 6, so A9 cannot be 6
Passo 17
Line/Unit Reduction
valore: 68.2
categoria doc: Intersection_Removal
Line/Box Reduction: 6s in box 2 remove the following in the same box:
- 6 can be removed from B6
Passo 18
Simple Colouring
valore: 169.2
categoria doc: Singles_Chains
(RULE 4): Uncoloured candidate 9 in F2 can see two different coloured candidates of 9 elsewhere.
Passo 19
Pointing Pairs
valore: 50.3
categoria doc: Intersection_Removal
Pair: between Box 4 and Row E:
- 9 can be removed from E8
Passo 20
X-Cycle
valore: 199.7
categoria doc: X_Cycles
X-CYCLE on 1 (Discontinuous Alternating Nice Loop, length 6):
+1[F8]-1[E7]+1[B7]-1[B4]+1[F4]-1[F8]
- Contradiction: When F8 is set to 1 the chain implies it cannot be 1 - it can be removed
Passo 21
XY-Chain
valore: 214.6
categoria doc: XY_Chains
length=4, chain ends: H7 and J4
This proves 8 is the solution at one or possibly both ends of the chain
-8[H7]+2[H7]-2[J9]+9[J9]-9[J5]+5[J5]-5[J4]+8[J4]
- 8 can be removed from H4
Passo 22
Hidden Singles
valore: 3.3
categoria doc: Getting_Started
8 in J4 is last in column/box
Passo 23
Rectangle Elimination
valore: 79.8
categoria doc: Rectangle_Elimination
If +5[H8] then -5[C8] forcing +5[C5] which removes all 5s from Box 8, so H8 cannot be 5
Passo 24
Hidden Pair
valore: 31.6
categoria doc: Hidden_Candidates
Hidden Pair 1/5 in Box 9, on cells {G8|G9}
- removes 8 from G8
Passo 25
Hidden Singles
valore: 3.1
categoria doc: Getting_Started
8 in G2 is last in row
Passo 26
Naked Singles
valore: 1.5
categoria doc: Getting_Started
Last candidate 3 in A2 changed to solution
Passo 27
Naked Singles
valore: 1.3
categoria doc: Getting_Started
Last candidate 8 in A1 changed to solution
Last candidate 4 in D2 changed to solution
Passo 28
Hidden Singles
valore: 2.5
categoria doc: Getting_Started
3 in D1 is last in row/column/box
4 in C1 is last in column/box
5 in E2 is last in column
Passo 29
Naked Singles
valore: 1.1
categoria doc: Getting_Started
Last candidate 1 in E1 changed to solution
Passo 30
Naked Singles
valore: 1.1
categoria doc: Getting_Started
Last candidate 9 in E3 changed to solution
Last candidate 6 in F1 changed to solution
Passo 31
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 1 in C3 changed to solution
Last candidate 2 in F2 changed to solution
Passo 32
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 9 in F9 changed to solution
Passo 33
Naked Singles
valore: 0.9
categoria doc: Getting_Started
Last candidate 4 in F8 changed to solution
Last candidate 2 in J9 changed to solution
Passo 34
Naked Singles
valore: 0.7
categoria doc: Getting_Started
Last candidate 1 in F4 changed to solution
Last candidate 8 in H7 changed to solution
Last candidate 5 in J1 changed to solution
Passo 35
Naked Singles
valore: 0.7
categoria doc: Getting_Started
Last candidate 2 in H1 changed to solution
Last candidate 9 in H8 changed to solution
Last candidate 9 in J5 changed to solution
Passo 36
Naked Singles
valore: 0.6
categoria doc: Getting_Started
Last candidate 5 in C5 changed to solution
Last candidate 4 in H6 changed to solution
Passo 37
Naked Singles
valore: 0.5
categoria doc: Getting_Started
Last candidate 4 in B4 changed to solution
Last candidate 2 in C8 changed to solution
Last candidate 5 in H4 changed to solution
Passo 38
Naked Singles
valore: 0.3
categoria doc: Getting_Started
Last candidate 6 in A5 changed to solution
Last candidate 6 in C7 changed to solution
Last candidate 8 in E8 changed to solution
Passo 39
Naked Singles
valore: 0.1
categoria doc: Getting_Started
Last candidate 1 in A6 changed to solution
Last candidate 1 in B7 changed to solution
Last candidate 9 in C2 changed to solution
Last candidate 1 in D8 changed to solution
Last candidate 4 in E5 changed to solution
Last candidate 6 in E6 changed to solution
Last candidate 2 in E7 changed to solution
Passo 40
Naked Singles
valore: 0
categoria doc: Getting_Started
Last candidate 4 in A9 changed to solution
Last candidate 6 in B2 changed to solution
Last candidate 9 in B6 changed to solution
Last candidate 5 in B9 changed to solution
Last candidate 8 in D6 changed to solution
Last candidate 6 in D9 changed to solution
Last candidate 5 in G8 changed to solution
Passo 41
Naked Singles
valore: 0
categoria doc: Getting_Started
Last candidate 1 in G9 changed to solution