Passi risolutivi (42)
Passo 1
Hidden Singles
valore: 5.9
categoria doc: Getting_Started
1 in B1 is last in row/box
3 in E2 is last in row/box
Passo 2
Hidden Singles
valore: 5.7
categoria doc: Getting_Started
1 in D2 is last in column/box
Passo 3
Hidden Singles
valore: 5.4
categoria doc: Getting_Started
1 in F9 is last in column/box
9 in J2 is last in column
Passo 4
Naked Pair
valore: 25.2
categoria doc: Naked_Candidates
Naked Pair 5/7 on cells {A2|C2} means
- 5/7 can be removed from A1
- 5 can be removed from B3
- 5 can be removed from C3
Last candidate 2 in B3 changed to solution
Passo 5
Naked Singles
valore: 2.4
categoria doc: Getting_Started
Last candidate 3 in H3 changed to solution
Passo 6
Hidden Pair
valore: 45.9
categoria doc: Hidden_Candidates
Hidden Pair 3/6 in Box 9, on cells {G7|J9}
- removes 2/9 from G7
- removes 4/8 from J9
Passo 7
Pointing Pairs
valore: 68.5
categoria doc: Intersection_Removal
Pair: between Box 9 and Row H:
- 4 can be removed from H5
Passo 8
Pointing Pairs
valore: 68.1
categoria doc: Intersection_Removal
Pair: between Box 9 and Col 8:
- 8 can be removed from A8
Passo 9
Rectangle Elimination
valore: 112.8
categoria doc: Rectangle_Elimination
If +7[F5] then -7[B5] forcing +7[B7] which removes all 7s from Box 6, so F5 cannot be 7
Passo 10
Hidden Unique Rectangle
valore: 448.4
categoria doc: Hidden_Unique_Rectangles
Type 1: removing 2 at G5 because of GJ58 and two strong links on 8
Passo 11
Forcing Nets
valore: 133.7
categoria doc: Forcing_Nets
If H9 is not 4 then both candidates in C7 are ON so H9 must be 4
Depth: 3 len: 8
-4[H9]+4[H7]-2[H7]+2[C7]
-4[H9]+9[H9]-9[C9]+9[C7]
Last candidate 4 in H9 changed to solution
Passo 12
Forcing Nets
valore: 345.5
categoria doc: Forcing_Nets
If F8 is not 7 then all 2s in Row D are removed so F8 must be 7
Depth: 8 len: 18
-7[F8]+7[A8]-7[B7]+7[B5]-7[H5]+7[H1]-2[H1]+2[H5]-2[D5]
-7[F8]+7[A8]-7[A2]+7[C2]-7[C4]+4[C4]-4[A6]+2[A6]-2[D6]
Last candidate 7 in F8 changed to solution
Passo 13
Hidden Pair
valore: 39.9
categoria doc: Hidden_Candidates
Hidden Pair 2/7 in Row D, on cells {D5|D6}
- removes 4/5/6/9 from D5
- removes 4/5/9 from D6
Passo 14
X-Wing
valore: 115.5
categoria doc: X_Wing_Strategy
(Row->Col) 5 taken off A2, based on AE68
(Row->Col) 5 taken off A5, based on AE68
(Row->Col) 5 taken off A9, based on AE68
(Row->Col) 5 taken off E1, based on AE68
(Row->Col) 5 taken off E5, based on AE68
Last candidate 7 in A2 changed to solution
Passo 15
Naked Singles
valore: 1.8
categoria doc: Getting_Started
Last candidate 5 in C2 changed to solution
Passo 16
X-Wing
valore: 106.5
categoria doc: X_Wing_Strategy
(Row->Col) 9 taken off E1, based on EG68
(Row->Col) 9 taken off E5, based on EG68
(Row->Col) 9 taken off G5, based on EG68
Passo 17
Hidden Pair
valore: 34.7
categoria doc: Hidden_Candidates
Hidden Pair 5/9 in Box 5, on cells {E6|F5}
- removes 4 from E6
- removes 4/6 from F5
Passo 18
XYZ Wing
valore: 206.3
categoria doc: XYZ_Wing
XYZ-Wing pattern. Hinge: D3 (4/5/6), wings E1 G3, therefore
- 6 can be removed from F3
Passo 19
Rectangle Elimination
valore: 85.3
categoria doc: Rectangle_Elimination
If +6[D9] then -6[D3] forcing +6[G3] which removes all 6s from Box 9, so D9 cannot be 6
Passo 20
Hidden Singles
valore: 3.4
categoria doc: Getting_Started
6 in J9 is last in column
Passo 21
Naked Singles
valore: 1.6
categoria doc: Getting_Started
Last candidate 3 in G7 changed to solution
Passo 22
Naked Singles
valore: 1.6
categoria doc: Getting_Started
Last candidate 7 in B7 changed to solution
Passo 23
Naked Pair
valore: 15.3
categoria doc: Naked_Candidates
Naked Pair 2/9 on cells {C7|H7} means
- 9 can be removed from D7
- 9 can be removed from F7
Passo 24
Naked Pair
valore: 14.9
categoria doc: Naked_Candidates
Naked Pair 4/6 on cells {F4|F7} means
- 4/6 can be removed from F1
- 4 can be removed from F3
Passo 25
Naked Pair
valore: 14.7
categoria doc: Naked_Candidates
Naked Pair 2/7 on cells {H1|J1} means
- 2 can be removed from G1
Passo 26
W-Wing
valore: 72.9
categoria doc: W_Wings
W-Wing (single). Either there is a 2 in D5 or in J1. They are connected through 7 in D6/J6, therefore
- 2 can be removed from J5
Passo 27
3D Medusa
valore: 231.1
categoria doc: 3D_Medusa
(RULE 3): 2 colors appear in a cell F1. The uncolored candidates 5 can be eliminated.
Passo 28
3D Medusa
valore: 228.9
categoria doc: 3D_Medusa
(RULE 5): Uncoloured candidate 4 in A6 can see coloured 4 elsewhere and an oppositely coloured 5 in its own cell. It can be removed.
Passo 29
Hidden Singles
valore: 2.8
categoria doc: Getting_Started
4 in J6 is last in column
Passo 30
Hidden Singles
valore: 2.7
categoria doc: Getting_Started
7 in D6 is last in column
Passo 31
Naked Singles
valore: 1.3
categoria doc: Getting_Started
Last candidate 2 in D5 changed to solution
Passo 32
Naked Pair
valore: 12.5
categoria doc: Naked_Candidates
Naked Pair 2/5 on cells {A6|A8} means
- 2 can be removed from A4
Passo 33
XY-Chain
valore: 257.1
categoria doc: XY_Chains
length=8. This XY-Chain is continuous and one value in each cell must be the solution, so all off-chain candidates can be removed
-4[C3]+8[C3]-8[C9]+9[C9]-9[C7]+2[C7]-2[A8]+5[A8]-5[A6]+2[A6]-2[G6]+9[G6]-9[H5]+7[H5]-7[C5]+4[C5]
- 7 can be removed from J5
- 4 can be removed from C4
Passo 34
XY-Chain
valore: 157.4
categoria doc: XY_Chains
length=4, chain ends: A6 and J8
This proves 2 is the solution at one or possibly both ends of the chain
-2[A6]+5[A6]-5[B5]+3[B5]-3[J5]+8[J5]-8[J8]+2[J8]
- 2 can be removed from A8
Last candidate 5 in A8 changed to solution
Passo 35
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 2 in A6 changed to solution
Last candidate 3 in B9 changed to solution
Last candidate 9 in E8 changed to solution
Passo 36
Naked Singles
valore: 0.8
categoria doc: Getting_Started
Last candidate 8 in A9 changed to solution
Last candidate 5 in B5 changed to solution
Last candidate 7 in C4 changed to solution
Last candidate 5 in D9 changed to solution
Last candidate 5 in E6 changed to solution
Last candidate 9 in G6 changed to solution
Passo 37
Naked Singles
valore: 0.6
categoria doc: Getting_Started
Last candidate 4 in A1 changed to solution
Last candidate 4 in C5 changed to solution
Last candidate 9 in C9 changed to solution
Last candidate 9 in F5 changed to solution
Last candidate 7 in H5 changed to solution
Passo 38
Naked Singles
valore: 0.5
categoria doc: Getting_Started
Last candidate 8 in C3 changed to solution
Last candidate 2 in C7 changed to solution
Last candidate 6 in E1 changed to solution
Last candidate 8 in F1 changed to solution
Last candidate 2 in H1 changed to solution
Passo 39
Naked Singles
valore: 0.3
categoria doc: Getting_Started
Last candidate 9 in D1 changed to solution
Last candidate 4 in D3 changed to solution
Last candidate 1 in E5 changed to solution
Last candidate 5 in F3 changed to solution
Last candidate 5 in G1 changed to solution
Last candidate 9 in H7 changed to solution
Last candidate 7 in J1 changed to solution
Passo 40
Naked Singles
valore: 0.2
categoria doc: Getting_Started
Last candidate 6 in D7 changed to solution
Last candidate 4 in E4 changed to solution
Last candidate 6 in G3 changed to solution
Last candidate 8 in G5 changed to solution
Passo 41
Naked Singles
valore: 0.1
categoria doc: Getting_Started
Last candidate 6 in F4 changed to solution
Last candidate 4 in F7 changed to solution
Last candidate 2 in G8 changed to solution
Last candidate 3 in J5 changed to solution
Passo 42
Naked Singles
valore: 0
categoria doc: Getting_Started
Last candidate 3 in A4 changed to solution
Last candidate 6 in A5 changed to solution
Last candidate 1 in G4 changed to solution
Last candidate 2 in J4 changed to solution
Last candidate 8 in J8 changed to solution