Passi risolutivi (20)
Passo 1
Hidden Singles
valore: 5
categoria doc: Getting_Started
6 in C6 is last in row/box
6 in H5 is last in column
7 in A2 is last in row
7 in G4 is last in row/column/box
8 in B7 is last in column/box
Passo 2
Hidden Singles
valore: 4.5
categoria doc: Getting_Started
7 in B9 is last in row/box
7 in E7 is last in column
8 in C4 is last in row/box
Passo 3
Hidden Singles
valore: 4
categoria doc: Getting_Started
2 in C8 is last in row
5 in B8 is last in row/box
5 in E9 is last in column
7 in D3 is last in row/column/box
Passo 4
Hidden Singles
valore: 3.5
categoria doc: Getting_Started
5 in F4 is last in row/box
6 in E1 is last in row
6 in F8 is last in box
6 in J9 is last in column
Passo 5
Hidden Singles
valore: 3.2
categoria doc: Getting_Started
3 in D9 is last in column
3 in J8 is last in box
Passo 6
Hidden Singles
valore: 3
categoria doc: Getting_Started
9 in G8 is last in column/box
Passo 7
Pointing Pairs
valore: 42.9
categoria doc: Intersection_Removal
Pair: between Box 5 and Row E:
- 3 can be removed from E3
Passo 8
Pointing Pairs
valore: 42.5
categoria doc: Intersection_Removal
Pair: between Box 8 and Col 6:
- 8 can be removed from D6
Passo 9
Line/Unit Reduction
valore: 55
categoria doc: Intersection_Removal
Line/Box Reduction: 2s in box 5 remove the following in the same box:
- 2 can be removed from D6
- 2 can be removed from E4
- 2 can be removed from E6
Passo 10
Naked Pair
valore: 13.5
categoria doc: Naked_Candidates
Naked Pair 1/4 on cells {D6|D8} means
- 1 can be removed from D2
- 4 can be removed from D5
Passo 11
Line/Unit Reduction
valore: 52.8
categoria doc: Intersection_Removal
Line/Box Reduction: 4s in box 2 remove the following in the same box:
- 4 can be removed from A4
- 4 can be removed from A6
Passo 12
Rectangle Elimination
valore: 65.3
categoria doc: Rectangle_Elimination
If +1[H3] then -1[H7] forcing +1[F7] which removes all 1s from box 4, so H3 cannot be 1
Passo 13
Rectangle Elimination
valore: 64.6
categoria doc: Rectangle_Elimination
If +1[B6] then -1[B3] forcing +1[E3] which removes all 1s from box 5, so B6 cannot be 1
Passo 14
Rectangle Elimination
valore: 64
categoria doc: Rectangle_Elimination
If +4[H6] then -4[H7] forcing +4[F7] which removes all 4s from box 5, so H6 cannot be 4
Passo 15
Simple Colouring
valore: 126.5
categoria doc: Singles_Chains
(RULE 4): Uncoloured candidate 4 in B6 can see two different coloured candidates of 4 elsewhere.
Passo 16
XY-Chain
valore: 210.5
categoria doc: XY_Chains
length=6, chain ends: B6 and E5
This proves 9 is the solution at one or possibly both ends of the chain
-9[B6]+3[B6]-3[B3]+1[B3]-1[E3]+2[E3]-2[D2]+8[D2]-8[D5]+2[D5]-2[E5]+9[E5]
- 9 can be removed from B5
- 9 can be removed from E6
Last candidate 4 in B5 changed to solution
Last candidate 8 in F5 changed to solution
Passo 17
Naked Singles
valore: 1.1
categoria doc: Getting_Started
Last candidate 2 in D5 changed to solution
Last candidate 9 in E5 changed to solution
Last candidate 8 in D2 changed to solution
Passo 18
Hidden Singles
valore: 1.8
categoria doc: Getting_Started
2 in E3 is last in row/box
4 in D6 is last in box
4 in F7 is last in row
4 in H4 is last in column
8 in G1 is last in column/box
8 in J6 is last in row
Passo 19
Naked Singles
valore: 0.2
categoria doc: Getting_Started
Last candidate 4 in A8 changed to solution
Last candidate 1 in B3 changed to solution
Last candidate 9 in C2 changed to solution
Last candidate 1 in C9 changed to solution
Last candidate 1 in G2 changed to solution
Last candidate 4 in G9 changed to solution
Last candidate 9 in H1 changed to solution
Last candidate 2 in H6 changed to solution
Last candidate 2 in J2 changed to solution
Last candidate 9 in J4 changed to solution
Last candidate 3 in A1 changed to solution
Last candidate 1 in A6 changed to solution
Last candidate 3 in B4 changed to solution
Last candidate 9 in B6 changed to solution
Last candidate 4 in C1 changed to solution
Last candidate 1 in E4 changed to solution
Last candidate 3 in E6 changed to solution
Last candidate 1 in F1 changed to solution
Last candidate 3 in F2 changed to solution
Last candidate 5 in H2 changed to solution
Passo 20
Naked Singles
valore: 0
categoria doc: Getting_Started
Last candidate 2 in A4 changed to solution