Passi risolutivi (23)
Passo 1
Naked Singles
valore: 2
categoria doc: Getting_Started
Last candidate 9 in E5 changed to solution
Last candidate 4 in F6 changed to solution
Last candidate 6 in J5 changed to solution
Last candidate 5 in A5 changed to solution
Last candidate 3 in D4 changed to solution
Passo 2
Hidden Singles
valore: 4.4
categoria doc: Getting_Started
1 in A1 is last in column
6 in G9 is last in row/box
9 in A6 is last in row
9 in B8 is last in column/box
9 in D2 is last in row/box
Passo 3
Hidden Singles
valore: 3.6
categoria doc: Getting_Started
4 in E8 is last in column
5 in E2 is last in column/box
Passo 4
Hidden Singles
valore: 3.4
categoria doc: Getting_Started
5 in H9 is last in column
Passo 5
Pointing Pairs
valore: 49.1
categoria doc: Intersection_Removal
Pair: between Box 9 and Col 8:
- 1 can be removed from D8
- 1 can be removed from F8
Last candidate 8 in F8 changed to solution
Passo 6
Pointing Pairs
valore: 44.2
categoria doc: Intersection_Removal
Pair: between Box 9 and Row J:
- 8 can be removed from J1
- 8 can be removed from J3
Passo 7
Rectangle Elimination
valore: 72.9
categoria doc: Rectangle_Elimination
If +7[J3] then -7[D3] forcing +7[D8] which removes all 7s from box 9, so J3 cannot be 7
Passo 8
XY-Chain
valore: 274.4
categoria doc: XY_Chains
length=7, chain ends: A7 and F3
This proves 2 is the solution at one or possibly both ends of the chain
-2[A7]+3[A7]-3[E7]+6[E7]-6[F7]+1[F7]-1[D7]+5[D7]-5[D8]+7[D8]-7[D3]+1[D3]-1[F3]+2[F3]
- 2 can be removed from A3
Passo 9
WXYZ Wing
valore: 286.1
categoria doc: WXYZ_Wing
WXYZ Wing Type 1: The four cells {B9,A7,A9,B1} contain in total 2/3/4/8 with the hinge on B9.
Non-Restricted candidate 2 determines the 'wing' cells (in yellow) and one of those 2s must be true. Therefore...
- 2 can be removed from A2
Passo 10
Hidden Singles
valore: 2.8
categoria doc: Getting_Started
2 in A7 is last in row
Passo 11
Y-Wing
valore: 106.7
categoria doc: Y_Wing_Strategy
Y-Wing pattern. Hinge: D8 (5/7), wings C8 E9, therefore
- 3 can be removed from A9
- 3 can be removed from B9
Last candidate 4 in A9 changed to solution
Last candidate 8 in B9 changed to solution
Passo 12
Naked Singles
valore: 1.1
categoria doc: Getting_Started
Last candidate 2 in B1 changed to solution
Last candidate 3 in B6 changed to solution
Last candidate 2 in C6 changed to solution
Last candidate 4 in B2 changed to solution
Passo 13
Hidden Singles
valore: 2
categoria doc: Getting_Started
8 in J7 is last in row/column/box
Passo 14
Naked Pair
valore: 9.9
categoria doc: Naked_Candidates
Naked Pair 3/7 on cells {A2|A3} means
- 3 can be removed from C2
Passo 15
XYZ Wing
valore: 117.2
categoria doc: XYZ_Wing
XYZ-Wing pattern. Hinge: H1 (7/8/9), wings H6 J1, therefore
- 7 can be removed from H2
Passo 16
Hidden Pair
valore: 19.3
categoria doc: Hidden_Candidates
Hidden Pair 3/7 in Col 2, on cells {A2|G2}
- removes 8 from G2
Passo 17
Unique Rectangle Type 1
valore: 37.4
categoria doc: Unique_Rectangle
Uniqueness Type 1 removing 3/7 at G3 because of A3,A2,G2
Passo 18
XY-Chain
valore: 138.2
categoria doc: XY_Chains
length=5, chain ends: J9 and H6
This proves 7 is the solution at one or possibly both ends of the chain
-7[J9]+3[J9]-3[E9]+7[E9]-7[E3]+8[E3]-8[G3]+8[G6]-7[G6]+7[H6]
- 7 can be removed from H8
Passo 19
XY-Chain
valore: 116.2
categoria doc: XY_Chains
length=4, chain ends: G4 and H8
This proves 1 is the solution at one or possibly both ends of the chain
-1[G4]+4[G4]-4[G3]+8[G3]-8[H2]+2[H2]-2[H8]+1[H8]
- 1 can be removed from G8
- 1 can be removed from H4
Last candidate 9 in H4 changed to solution
Last candidate 4 in J4 changed to solution
Passo 20
Naked Singles
valore: 0.8
categoria doc: Getting_Started
Last candidate 1 in G4 changed to solution
Passo 21
Hidden Singles
valore: 1.5
categoria doc: Getting_Started
1 in H8 is last in row/column/box
4 in G3 is last in row/column/box
9 in J1 is last in row/column/box
Passo 22
Hidden Singles
valore: 1.3
categoria doc: Getting_Started
2 in H2 is last in row
2 in J8 is last in column/box
8 in E3 is last in column
8 in G6 is last in row
Passo 23
Naked Singles
valore: 0.1
categoria doc: Getting_Started
Last candidate 7 in A3 changed to solution
Last candidate 1 in D3 changed to solution
Last candidate 5 in D7 changed to solution
Last candidate 7 in D8 changed to solution
Last candidate 3 in E9 changed to solution
Last candidate 6 in F2 changed to solution
Last candidate 2 in F3 changed to solution
Last candidate 1 in F7 changed to solution
Last candidate 7 in G2 changed to solution
Last candidate 3 in G8 changed to solution
Last candidate 8 in H1 changed to solution
Last candidate 3 in A2 changed to solution
Last candidate 6 in C1 changed to solution
Last candidate 8 in C2 changed to solution
Last candidate 3 in C7 changed to solution
Last candidate 5 in C8 changed to solution
Last candidate 7 in E1 changed to solution
Last candidate 6 in E7 changed to solution