Passi risolutivi (37)
Passo 1
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 6 in H4 changed to solution
Passo 2
Hidden Singles
valore: 5.5
categoria doc: Getting_Started
5 in H2 is last in row
6 in A7 is last in row
6 in B6 is last in column/box
7 in E3 is last in row
9 in J5 is last in row/box
Passo 3
Hidden Singles
valore: 4.7
categoria doc: Getting_Started
4 in G3 is last in box
4 in H8 is last in row
8 in J3 is last in row
Passo 4
Hidden Singles
valore: 4
categoria doc: Getting_Started
4 in A5 is last in row
6 in F3 is last in column
6 in G1 is last in box
6 in J9 is last in row
Passo 5
Naked Pair
valore: 18.6
categoria doc: Naked_Candidates
Naked Pair 3/7 on cells {G6|H5} means
- 3/7 can be removed from G5
Passo 6
Naked Pair
valore: 18.4
categoria doc: Naked_Candidates
Naked Pair 2/8 on cells {G4|G5} means
- 2 can be removed from G7
Passo 7
Hidden Pair
valore: 35.8
categoria doc: Hidden_Candidates
Hidden Pair 2/5 in Box 5, on cells {D4|F5}
- removes 1/9 from D4
- removes 1/3 from F5
Passo 8
Pointing Pairs
valore: 53.2
categoria doc: Intersection_Removal
Pair: between Box 5 and Row E:
- 1 can be removed from E7
Passo 9
Pointing Pairs
valore: 52.8
categoria doc: Intersection_Removal
Pair: between Box 2 and Row C:
- 7 can be removed from C1
Passo 10
Rectangle Elimination
valore: 87.3
categoria doc: Rectangle_Elimination
If +3[E7] then -3[G7] forcing +3[G6] which removes all 3s from Box 5, so E7 cannot be 3
Passo 11
Line/Unit Reduction
valore: 69.3
categoria doc: Intersection_Removal
Line/Box Reduction: 3s in box 5 remove the following in the same box:
- 3 can be removed from F6
Passo 12
WXYZ Wing
valore: 343.9
categoria doc: WXYZ_Wing
WXYZ Wing Type 1: The four cells {B5,B2,B9,F5} contain in total 1/2/5/8 with the hinge on B5.
Non-Restricted candidate 2 determines the 'wing' cells (in yellow) and one of those 2s must be true. Therefore...
- 2 can be removed from F2
Passo 13
WXYZ Wing
valore: 332.9
categoria doc: WXYZ_Wing
WXYZ Wing Type 2: The four cells {B8,B9,A8,B2} contain in total 1/2/8/9.
Hinge cells (orange) contains WXYZ and 'wing' cells (in yellow) contain WY and XZ respectively. Therefore...
1 can be taken off B3 (Row)
1 can be taken off B5 (Row)
9 can be taken off C7 (Box)
8 can be taken off C9 (Box)
Passo 14
Pointing Pairs
valore: 49.1
categoria doc: Intersection_Removal
Pair: between Box 3 and Col 8:
- 9 can be removed from D8
- 9 can be removed from F8
Passo 15
Naked Triple
valore: 64.9
categoria doc: Naked_Candidates
Naked Triple 2/5/8 on cells {B5|F5|G5} means
- 8 can be removed from C5
Passo 16
W-Wing
valore: 80.5
categoria doc: W_Wings
W-Wing (single). Either there is a 3 in D8 or in H1. They are connected through 7 in J8/J2, therefore
- 3 can be removed from D1
Passo 17
Rectangle Elimination
valore: 79.8
categoria doc: Rectangle_Elimination
If +1[D9] then -1[B9] forcing +1[B2] which removes all 1s from Box 4, so D9 cannot be 1
Passo 18
XY-Chain
valore: 205.6
categoria doc: XY_Chains
length=4, chain ends: C9 and F6
This proves 4 is the solution at one or possibly both ends of the chain
-4[C9]+1[C9]-1[C5]+7[C5]-7[C6]+9[C6]-9[F6]+4[F6]
- 4 can be removed from F9
Passo 19
XY-Chain
valore: 261.9
categoria doc: XY_Chains
length=6, chain ends: B3 and D1
This proves 9 is the solution at one or possibly both ends of the chain
-9[B3]+5[B3]-5[B5]+8[B5]-8[G5]+2[G5]-2[F5]+5[F5]-5[D4]+2[D4]-2[D1]+9[D1]
- 9 can be removed from A1
- 9 can be removed from C1
- 9 can be removed from D3
Passo 20
XY-Chain
valore: 257.2
categoria doc: XY_Chains
length=6, chain ends: C9 and E7
This proves 4 is the solution at one or possibly both ends of the chain
-4[C9]+1[C9]-1[C5]+7[C5]-7[H5]+3[H5]-3[E5]+1[E5]-1[E4]+9[E4]-9[E7]+4[E7]
- 4 can be removed from C7
- 4 can be removed from D9
Passo 21
Hidden Singles
valore: 3
categoria doc: Getting_Started
4 in C9 is last in row/column/box
Passo 22
Naked Pair
valore: 14.7
categoria doc: Naked_Candidates
Naked Pair 5/7 on cells {D9|G9} means
- 5 can be removed from F9
Passo 23
XY-Chain
valore: 189.5
categoria doc: XY_Chains
length=4, chain ends: A2 and C7
This proves 1 is the solution at one or possibly both ends of the chain
-1[A2]+7[A2]-7[J2]+3[J2]-3[J7]+2[J7]-2[C7]+1[C7]
- 1 can be removed from C3
Passo 24
XY-Chain
valore: 216.6
categoria doc: XY_Chains
length=5, chain ends: H1 and C3
This proves 3 is the solution at one or possibly both ends of the chain
-3[H1]+7[H1]-7[H5]+3[H5]-3[G6]+7[G6]-7[C6]+9[C6]-9[C3]+3[C3]
- 3 can be removed from C1
Passo 25
Hidden Singles
valore: 2.9
categoria doc: Getting_Started
3 in C3 is last in row/box
Passo 26
Naked Singles
valore: 1.3
categoria doc: Getting_Started
Last candidate 1 in D3 changed to solution
Passo 27
Line/Unit Reduction
valore: 52.8
categoria doc: Intersection_Removal
Line/Box Reduction: 9s in box 2 remove the following in the same box:
- 9 can be removed from A4
Passo 28
XY-Chain
valore: 193.9
categoria doc: XY_Chains
length=5, chain ends: C6 and H5
This proves 7 is the solution at one or possibly both ends of the chain
-7[C6]+9[C6]-9[F6]+4[F6]-4[F2]+3[F2]-3[J2]+3[H1]-7[H1]+7[H5]
- 7 can be removed from C5
- 7 can be removed from G6
Last candidate 1 in C5 changed to solution
Last candidate 3 in G6 changed to solution
Passo 29
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 2 in C7 changed to solution
Last candidate 3 in E5 changed to solution
Last candidate 5 in G7 changed to solution
Last candidate 7 in H5 changed to solution
Passo 30
Naked Singles
valore: 0.8
categoria doc: Getting_Started
Last candidate 8 in C1 changed to solution
Last candidate 7 in G9 changed to solution
Last candidate 3 in H1 changed to solution
Last candidate 3 in J7 changed to solution
Passo 31
Naked Singles
valore: 0.7
categoria doc: Getting_Started
Last candidate 7 in A1 changed to solution
Last candidate 9 in C4 changed to solution
Last candidate 5 in D9 changed to solution
Last candidate 7 in J2 changed to solution
Last candidate 2 in J8 changed to solution
Passo 32
Naked Singles
valore: 0.6
categoria doc: Getting_Started
Last candidate 1 in A2 changed to solution
Last candidate 7 in C6 changed to solution
Last candidate 2 in D4 changed to solution
Last candidate 1 in E4 changed to solution
Passo 33
Naked Singles
valore: 0.5
categoria doc: Getting_Started
Last candidate 2 in B2 changed to solution
Last candidate 9 in D1 changed to solution
Last candidate 5 in F5 changed to solution
Last candidate 8 in G4 changed to solution
Passo 34
Naked Singles
valore: 0.3
categoria doc: Getting_Started
Last candidate 5 in A4 changed to solution
Last candidate 8 in B5 changed to solution
Last candidate 4 in D7 changed to solution
Last candidate 2 in F1 changed to solution
Last candidate 2 in G5 changed to solution
Passo 35
Naked Singles
valore: 0.2
categoria doc: Getting_Started
Last candidate 9 in A3 changed to solution
Last candidate 9 in B8 changed to solution
Last candidate 1 in B9 changed to solution
Last candidate 3 in D2 changed to solution
Last candidate 9 in E7 changed to solution
Passo 36
Naked Singles
valore: 0
categoria doc: Getting_Started
Last candidate 8 in A8 changed to solution
Last candidate 5 in B3 changed to solution
Last candidate 7 in D8 changed to solution
Last candidate 4 in E6 changed to solution
Last candidate 4 in F2 changed to solution
Last candidate 1 in F7 changed to solution
Last candidate 8 in F9 changed to solution
Passo 37
Naked Singles
valore: 0
categoria doc: Getting_Started
Last candidate 9 in F6 changed to solution
Last candidate 3 in F8 changed to solution