Passi risolutivi (44)
Passo 1
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 5 in G3 changed to solution
Passo 2
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 7 in G2 changed to solution
Passo 3
Hidden Singles
valore: 5.1
categoria doc: Getting_Started
3 in H1 is last in column/box
4 in C2 is last in column/box
7 in D6 is last in row/box
7 in J8 is last in column/box
Passo 4
Hidden Singles
valore: 4.7
categoria doc: Getting_Started
3 in J9 is last in column
7 in H5 is last in row/column/box
Passo 5
Pointing Pairs
valore: 66.9
categoria doc: Intersection_Removal
Pair: between Box 6 and Col 8:
- 1 can be removed from A8
- 1 can be removed from C8
Passo 6
Pointing Pairs
valore: 66.4
categoria doc: Intersection_Removal
Pair: between Box 9 and Col 7:
- 2 can be removed from D7
Passo 7
Hidden Triple
valore: 107.3
categoria doc: Hidden_Candidates
Hidden Triple 1/5/9 in Col 4, on cells {A4|H4|J4}
- removes 2/3/8 from A4
- removes 4/8 from H4
Passo 8
Pointing Pairs
valore: 64
categoria doc: Intersection_Removal
Pair: between Box 2 and Col 5:
- 2 can be removed from E5
Passo 9
Hidden Triple
valore: 105.2
categoria doc: Hidden_Candidates
Hidden Triple 3/4/8 in Box 8, on cells {G4|G5|H6}
- removes 6 from G5
- removes 1 from H6
Passo 10
Pointing Pairs
valore: 62.7
categoria doc: Intersection_Removal
Pair: between Box 8 and Row J:
- 6 can be removed from J7
Passo 11
Aligned Pair Exclusion
valore: 581.6
categoria doc: Aligned_Pair_Exclusion
Some solution combinations in the two gray cells would empty at least one of the coloured cells. Removing those combinations create eliminations in the gray cells.
Pair D7 / G8 reduced from 5/8/9->5/8 and 4/6->4/6
- Combinations of 2/6/8/9 found in ALS {G7,H7,J7}
Note: some ALSs share cells and cannot be fully colour indicated
Passo 12
Y-Wing
valore: 162.9
categoria doc: Y_Wing_Strategy
Y-Wing pattern. Hinge: F9 (8/9), wings B9 D7, therefore
- 5 can be removed from B7
- 5 can be removed from C7
- 5 can be removed from E9
Passo 13
Hidden Singles
valore: 3.9
categoria doc: Getting_Started
5 in B9 is last in column/box
5 in C6 is last in row
5 in D7 is last in column/box
Passo 14
Naked Singles
valore: 1.7
categoria doc: Getting_Started
Last candidate 2 in D1 changed to solution
Passo 15
Hidden Singles
valore: 3.3
categoria doc: Getting_Started
5 in J4 is last in row/column/box
Passo 16
Hidden Pair
valore: 32.5
categoria doc: Hidden_Candidates
Hidden Pair 1/2 in Box 6, on cells {E8|F8}
- removes 4 from E8
- removes 9 from F8
Passo 17
Pointing Pairs
valore: 48.3
categoria doc: Intersection_Removal
Pair: between Box 6 and Col 9:
- 8 can be removed from H9
Passo 18
Y-Wing
valore: 127.6
categoria doc: Y_Wing_Strategy
Y-Wing pattern. Hinge: D8 (4/9), wings D2 E9, therefore
- 8 can be removed from E2
Passo 19
Y-Wing
valore: 125.4
categoria doc: Y_Wing_Strategy
Y-Wing pattern. Hinge: D8 (4/9), wings D4 F9, therefore
- 8 can be removed from F4
- 8 can be removed from F6
Passo 20
Rectangle Elimination
valore: 77.7
categoria doc: Rectangle_Elimination
If +1[A2] then -1[A4] forcing +1[H4] which removes all 1s from Box 7, so A2 cannot be 1
Passo 21
X-Cycle
valore: 231.1
categoria doc: X_Cycles
X-CYCLE on 9 (Discontinuous Alternating Nice Loop, length 8):
+9[A2]-9[A4]+9[H4]-9[H9]+9[F9]-9[D8]+9[D2]-9[A2]
- Contradiction: When A2 is set to 9 the chain implies it cannot be 9 - it can be removed
Passo 22
Pointing Pairs
valore: 45.8
categoria doc: Intersection_Removal
Triple: between Box 1 and Col 3:
- 9 can be removed from F3
Passo 23
XY-Chain
valore: 257.2
categoria doc: XY_Chains
length=6, chain ends: F8 and H3
This proves 1 is the solution at one or possibly both ends of the chain
-1[F8]+2[F8]-2[F4]+3[F4]-3[F6]+6[F6]-6[J6]+1[J6]-1[J2]+2[J2]-2[H3]+1[H3]
- 1 can be removed from F3
Passo 24
3D Medusa
valore: 239.9
categoria doc: 3D_Medusa
(RULE 4): Uncoloured candidate 1 in E2 can see two different coloured candidates of 1 elsewhere.
Last candidate 5 in E2 changed to solution
Passo 25
Hidden Singles
valore: 2.9
categoria doc: Getting_Started
5 in A1 is last in row/column/box
Passo 26
3D Medusa
valore: 222.3
categoria doc: 3D_Medusa
(RULE 5): Uncoloured candidate 1 in B7 can see coloured 1 elsewhere and an oppositely coloured 6 in its own cell. It can be removed.
(RULE 5): Uncoloured candidate 8 in A3 can see coloured 8 elsewhere and an oppositely coloured 6 in its own cell. It can be removed.
Passo 27
Hidden Singles
valore: 2.8
categoria doc: Getting_Started
1 in C7 is last in column/box
Passo 28
XY-Chain
valore: 200.1
categoria doc: XY_Chains
length=5, chain ends: C3 and J5
This proves 9 is the solution at one or possibly both ends of the chain
-9[C3]+8[C3]-8[A2]+2[A2]-2[J2]+1[J2]-1[J6]+6[J6]-6[J5]+9[J5]
- 9 can be removed from C5
Passo 29
XY-Chain
valore: 171.7
categoria doc: XY_Chains
length=4, chain ends: C5 and G7
This proves 8 is the solution at one or possibly both ends of the chain
-8[C5]+3[C5]-3[C8]+9[C8]-9[B7]+6[B7]-6[G7]+8[G7]
- 8 can be removed from G5
Passo 30
Y-Wing
valore: 104.5
categoria doc: Y_Wing_Strategy
Y-Wing pattern. Hinge: G5 (3/4), wings C5 H6, therefore
- 8 can be removed from A6
Passo 31
Hidden Singles
valore: 2.6
categoria doc: Getting_Started
8 in H6 is last in column
Passo 32
Hidden Singles
valore: 2.4
categoria doc: Getting_Started
4 in B6 is last in column
4 in H9 is last in row
8 in G7 is last in row/column/box
Passo 33
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 8 in E9 changed to solution
Last candidate 6 in G8 changed to solution
Passo 34
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 9 in F9 changed to solution
Passo 35
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 4 in D8 changed to solution
Passo 36
Naked Singles
valore: 0.9
categoria doc: Getting_Started
Last candidate 8 in D4 changed to solution
Passo 37
Naked Singles
valore: 0.9
categoria doc: Getting_Started
Last candidate 9 in D2 changed to solution
Passo 38
Hidden Singles
valore: 1.8
categoria doc: Getting_Started
6 in A3 is last in row
6 in B7 is last in column/box
Passo 39
Naked Singles
valore: 0.7
categoria doc: Getting_Started
Last candidate 1 in B1 changed to solution
Last candidate 8 in F3 changed to solution
Passo 40
Naked Singles
valore: 0.6
categoria doc: Getting_Started
Last candidate 9 in C3 changed to solution
Last candidate 6 in E1 changed to solution
Last candidate 1 in F2 changed to solution
Passo 41
Naked Singles
valore: 0.4
categoria doc: Getting_Started
Last candidate 2 in B3 changed to solution
Last candidate 3 in C8 changed to solution
Last candidate 4 in E5 changed to solution
Last candidate 2 in F8 changed to solution
Last candidate 2 in J2 changed to solution
Passo 42
Naked Singles
valore: 0.2
categoria doc: Getting_Started
Last candidate 8 in A2 changed to solution
Last candidate 9 in A8 changed to solution
Last candidate 9 in B5 changed to solution
Last candidate 8 in C5 changed to solution
Last candidate 2 in E4 changed to solution
Last candidate 1 in E8 changed to solution
Last candidate 3 in F4 changed to solution
Last candidate 3 in G5 changed to solution
Last candidate 1 in H3 changed to solution
Last candidate 9 in J7 changed to solution
Passo 43
Naked Singles
valore: 0
categoria doc: Getting_Started
Last candidate 1 in A4 changed to solution
Last candidate 2 in A5 changed to solution
Last candidate 6 in F6 changed to solution
Last candidate 4 in G4 changed to solution
Last candidate 9 in H4 changed to solution
Last candidate 2 in H7 changed to solution
Last candidate 6 in J5 changed to solution
Passo 44
Naked Singles
valore: 0
categoria doc: Getting_Started
Last candidate 3 in A6 changed to solution
Last candidate 1 in J6 changed to solution