Passi risolutivi (45)
Passo 1
Naked Singles
valore: 2
categoria doc: Getting_Started
Last candidate 2 in F9 changed to solution
Last candidate 1 in H9 changed to solution
Passo 2
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 7 in H8 changed to solution
Passo 3
Naked Singles
valore: 2.6
categoria doc: Getting_Started
Last candidate 4 in H2 changed to solution
Passo 4
Naked Singles
valore: 2.4
categoria doc: Getting_Started
Last candidate 8 in B2 changed to solution
Passo 5
Naked Singles
valore: 2.4
categoria doc: Getting_Started
Last candidate 3 in B1 changed to solution
Passo 6
Naked Singles
valore: 2.3
categoria doc: Getting_Started
Last candidate 4 in B3 changed to solution
Passo 7
Hidden Singles
valore: 4.5
categoria doc: Getting_Started
1 in A8 is last in row/column/box
1 in F5 is last in row
Passo 8
Hidden Singles
valore: 4.3
categoria doc: Getting_Started
2 in B8 is last in column/box
7 in F6 is last in row
Passo 9
Naked Pair
valore: 20.4
categoria doc: Naked_Candidates
Naked Pair 5/9 on cells {B7|C8} means
- 5/9 can be removed from C7
- 5 can be removed from C9
Passo 10
Pointing Pairs
valore: 60.2
categoria doc: Intersection_Removal
Pair: between Box 6 and Row E:
- 4 can be removed from E4
- 4 can be removed from E5
Passo 11
Pointing Pairs
valore: 59.4
categoria doc: Intersection_Removal
Triple: between Box 6 and Row E:
- 5 can be removed from E5
- 5 can be removed from E6
Passo 12
Pointing Pairs
valore: 58.6
categoria doc: Intersection_Removal
Pair: between Box 9 and Row J:
- 8 can be removed from J1
- 8 can be removed from J3
Passo 13
Rectangle Elimination
valore: 97
categoria doc: Rectangle_Elimination
If +6[G4] then -6[F4] forcing +6[F7] which removes all 6s from Box 9, so G4 cannot be 6
Passo 14
Rectangle Elimination
valore: 96.3
categoria doc: Rectangle_Elimination
If +9[E5] then -9[B5] forcing +9[B7] which removes all 9s from Box 6, so E5 cannot be 9
Passo 15
Rectangle Elimination
valore: 95.6
categoria doc: Rectangle_Elimination
If +9[C4] then -9[F4] forcing +9[F7] which removes all 9s from Box 3, so C4 cannot be 9
Passo 16
Line/Unit Reduction
valore: 74.8
categoria doc: Intersection_Removal
Line/Box Reduction: 9s in box 5 remove the following in the same box:
- 9 can be removed from D5
- 9 can be removed from D6
- 9 can be removed from E6
Passo 17
X-Cycle
valore: 278.5
categoria doc: X_Cycles
X-CYCLE on 9 (Discontinuous Alternating Nice Loop, length 8):
+9[E3]-9[E8]+9[C8]-9[B7]+9[B5]-9[H5]+9[H3]-9[E3]
- Contradiction: When E3 is set to 9 the chain implies it cannot be 9 - it can be removed
Passo 18
XY-Chain
valore: 272.4
categoria doc: XY_Chains
length=5, chain ends: A7 and J9
This proves 8 is the solution at one or possibly both ends of the chain
-8[A7]+7[A7]-7[A3]+6[A3]-6[C2]+7[C2]-7[J2]+5[J2]-5[J9]+8[J9]
- 8 can be removed from A9
- 8 can be removed from C9
- 8 can be removed from J7
Last candidate 3 in A9 changed to solution
Passo 19
Naked Singles
valore: 1.7
categoria doc: Getting_Started
Last candidate 4 in C9 changed to solution
Passo 20
Naked Singles
valore: 1.7
categoria doc: Getting_Started
Last candidate 5 in E9 changed to solution
Passo 21
Naked Singles
valore: 1.7
categoria doc: Getting_Started
Last candidate 8 in J9 changed to solution
Passo 22
Hidden Singles
valore: 3.2
categoria doc: Getting_Started
4 in E7 is last in row/column/box
Passo 23
XY-Chain
valore: 239.3
categoria doc: XY_Chains
length=5, chain ends: E8 and C2
This proves 6 is the solution at one or possibly both ends of the chain
-6[E8]+9[E8]-9[F7]+6[F7]-6[J7]+5[J7]-5[J2]+7[J2]-7[C2]+6[C2]
- 6 can be removed from E2
Passo 24
Hidden Singles
valore: 3.2
categoria doc: Getting_Started
6 in C2 is last in column
Passo 25
Naked Singles
valore: 1.4
categoria doc: Getting_Started
Last candidate 7 in A3 changed to solution
Passo 26
Naked Singles
valore: 1.4
categoria doc: Getting_Started
Last candidate 8 in A7 changed to solution
Passo 27
Naked Singles
valore: 1.4
categoria doc: Getting_Started
Last candidate 7 in C7 changed to solution
Passo 28
Hidden Pair
valore: 27
categoria doc: Hidden_Candidates
Hidden Pair 1/7 in Box 4, on cells {E1|E2}
- removes 8/9 from E1
Passo 29
Pointing Pairs
valore: 40
categoria doc: Intersection_Removal
Pair: between Box 4 and Row D:
- 9 can be removed from D4
Passo 30
Y-Wing
valore: 105.6
categoria doc: Y_Wing_Strategy
Y-Wing pattern. Hinge: G3 (2/8), wings E3 G6, therefore
- 6 can be removed from E6
Passo 31
X-Cycle
valore: 196
categoria doc: X_Cycles
X-CYCLE on 6 (Discontinuous Alternating Nice Loop, length 8):
+6[G5]-6[G8]+6[J7]-6[F7]+6[F4]-6[A4]+6[A5]-6[G5]
- Contradiction: When G5 is set to 6 the chain implies it cannot be 6 - it can be removed
Passo 32
XY-Chain
valore: 193.9
categoria doc: XY_Chains
length=5, chain ends: D6 and C8
This proves 5 is the solution at one or possibly both ends of the chain
-5[D6]+6[D6]-6[F4]+9[F4]-9[F7]+6[F7]-6[E8]+9[E8]-9[C8]+5[C8]
- 5 can be removed from C6
Passo 33
Hidden Singles
valore: 2.6
categoria doc: Getting_Started
5 in D6 is last in column
Passo 34
Line/Unit Reduction
valore: 49.5
categoria doc: Intersection_Removal
Line/Box Reduction: 6s in box 8 remove the following in the same box:
- 6 can be removed from J5
Passo 35
XY-Chain
valore: 208.1
categoria doc: XY_Chains
length=6, chain ends: G6 and A4
This proves 2 is the solution at one or possibly both ends of the chain
-2[G6]+6[G6]-6[G8]+5[G8]-5[J7]+6[J7]-6[F7]+9[F7]-9[F4]+6[F4]-6[A4]+2[A4]
- 2 can be removed from G4
Last candidate 4 in G4 changed to solution
Passo 36
Hidden Singles
valore: 2.3
categoria doc: Getting_Started
4 in D5 is last in row/column/box
Passo 37
XY-Chain
valore: 167.1
categoria doc: XY_Chains
length=5, chain ends: C6 and B7
This proves 9 is the solution at one or possibly both ends of the chain
-9[C6]+3[C6]-3[C4]+8[C4]-8[D4]+6[D4]-6[F4]+6[F7]-9[F7]+9[B7]
- 9 can be removed from B5
- 9 can be removed from C8
Last candidate 5 in B5 changed to solution
Last candidate 5 in C8 changed to solution
Passo 38
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 9 in B7 changed to solution
Last candidate 6 in G8 changed to solution
Passo 39
Naked Singles
valore: 0.8
categoria doc: Getting_Started
Last candidate 9 in E8 changed to solution
Last candidate 6 in F7 changed to solution
Last candidate 2 in G6 changed to solution
Last candidate 5 in J7 changed to solution
Passo 40
Naked Singles
valore: 0.6
categoria doc: Getting_Started
Last candidate 3 in E6 changed to solution
Last candidate 9 in F4 changed to solution
Last candidate 8 in G3 changed to solution
Last candidate 7 in G5 changed to solution
Last candidate 7 in J2 changed to solution
Passo 41
Naked Singles
valore: 0.3
categoria doc: Getting_Started
Last candidate 9 in C6 changed to solution
Last candidate 1 in E2 changed to solution
Last candidate 6 in E3 changed to solution
Last candidate 1 in G1 changed to solution
Last candidate 9 in J1 changed to solution
Passo 42
Naked Singles
valore: 0.2
categoria doc: Getting_Started
Last candidate 8 in D1 changed to solution
Last candidate 9 in D3 changed to solution
Last candidate 7 in E1 changed to solution
Last candidate 5 in G2 changed to solution
Last candidate 3 in H3 changed to solution
Last candidate 3 in J5 changed to solution
Last candidate 6 in J6 changed to solution
Passo 43
Naked Singles
valore: 0.1
categoria doc: Getting_Started
Last candidate 8 in C5 changed to solution
Last candidate 6 in D4 changed to solution
Last candidate 9 in H5 changed to solution
Last candidate 2 in J3 changed to solution
Passo 44
Naked Singles
valore: 0
categoria doc: Getting_Started
Last candidate 2 in A4 changed to solution
Last candidate 3 in C4 changed to solution
Last candidate 2 in E5 changed to solution
Passo 45
Naked Singles
valore: 0
categoria doc: Getting_Started
Last candidate 6 in A5 changed to solution
Last candidate 8 in E4 changed to solution