Passi risolutivi (42)
Passo 1
Hidden Singles
valore: 5.6
categoria doc: Getting_Started
5 in J8 is last in column/box
6 in A3 is last in column/box
6 in H4 is last in column/box
8 in B4 is last in row/box
8 in H8 is last in row/box
Passo 2
Hidden Singles
valore: 5
categoria doc: Getting_Started
4 in G4 is last in column/box
8 in E6 is last in row
Passo 3
Hidden Singles
valore: 4.8
categoria doc: Getting_Started
5 in G6 is last in row/box
Passo 4
Hidden Singles
valore: 4.6
categoria doc: Getting_Started
2 in J6 is last in box
Passo 5
Hidden Singles
valore: 4.5
categoria doc: Getting_Started
2 in G3 is last in column
Passo 6
Hidden Pair
valore: 43.2
categoria doc: Hidden_Candidates
Hidden Pair 1/3 in Row J, on cells {J2|J5}
- removes 4/9 from J2
- removes 9 from J5
Passo 7
Pointing Pairs
valore: 64
categoria doc: Intersection_Removal
Pair: between Box 3 and Col 8:
- 3 can be removed from D8
- 3 can be removed from F8
Passo 8
Pointing Pairs
valore: 63.5
categoria doc: Intersection_Removal
Pair: between Box 5 and Col 4:
- 5 can be removed from A4
Passo 9
Pointing Pairs
valore: 62.7
categoria doc: Intersection_Removal
Pair: between Box 9 and Col 9:
- 7 can be removed from E9
- 7 can be removed from F9
Passo 10
Pointing Pairs
valore: 61.5
categoria doc: Intersection_Removal
Pair: between Box 8 and Row H:
- 9 can be removed from H1
- 9 can be removed from H2
- 9 can be removed from H9
Passo 11
Line/Unit Reduction
valore: 79.8
categoria doc: Intersection_Removal
Line/Box Reduction: 7s in box 4 remove the following in the same box:
- 7 can be removed from D1
- 7 can be removed from D2
- 7 can be removed from E1
- 7 can be removed from F2
Passo 12
Hidden Singles
valore: 4
categoria doc: Getting_Started
7 in E5 is last in row
Passo 13
Hidden Singles
valore: 3.8
categoria doc: Getting_Started
7 in C6 is last in column/box
Passo 14
Rectangle Elimination
valore: 91.5
categoria doc: Rectangle_Elimination
If +4[J9] then -4[J3] forcing +4[D3] which removes all 4s from Box 6, so J9 cannot be 4
Passo 15
X-Cycle
valore: 250.3
categoria doc: X_Cycles
X-Cycle Rule 1:+4[D3]-4[E1]+4[E9]-4[H9]+4[J7]-4[J3]+4[D3]
- Off-chain 4 taken off D1 - weak link: (4)D3 - to (4)E1 =
- Off-chain 4 taken off D2 - weak link: (4)D3 - to (4)E1 =
- Off-chain 4 taken off B9 - weak link: (4)E9 - to (4)H9 =
Passo 16
XY-Chain
valore: 264.1
categoria doc: XY_Chains
length=5, chain ends: D7 and J3
This proves 4 is the solution at one or possibly both ends of the chain
-4[D7]+8[D7]-8[F7]+6[F7]-6[F8]+7[F8]-7[F3]+9[F3]-9[J3]+4[J3]
- 4 can be removed from D3
- 4 can be removed from J7
Passo 17
Hidden Singles
valore: 3.4
categoria doc: Getting_Started
4 in E1 is last in box
4 in H9 is last in box
4 in J3 is last in row/column
Passo 18
Hidden Singles
valore: 3.2
categoria doc: Getting_Started
7 in G9 is last in column/box
9 in G2 is last in box
Passo 19
Naked Pair
valore: 14.7
categoria doc: Naked_Candidates
Naked Pair 7/9 on cells {D3|F3} means
- 9 can be removed from D1
Passo 20
XY-Chain
valore: 247.9
categoria doc: XY_Chains
length=6, chain ends: A8 and E4
This proves 3 is the solution at one or possibly both ends of the chain
-3[A8]+2[A8]-2[B9]+9[B9]-9[J9]+6[J9]-6[F9]+3[F9]-3[E9]+2[E9]-2[E4]+3[E4]
- 3 can be removed from A4
Passo 21
Naked Pair
valore: 13.9
categoria doc: Naked_Candidates
Naked Pair 1/9 on cells {A4|A7} means
- 1/9 can be removed from A1
- 1 can be removed from A2
- 1/9 can be removed from A5
Passo 22
Chute Remote Pair
valore: 68.8
categoria doc: Chute_Remote_Pairs
1 cannot be set in the yellow cells {B7,B8,B9} and with the Remote Pair in A4 and C1 it means:
- 9 can be removed from C4
Passo 23
X-Cycle
valore: 204.3
categoria doc: X_Cycles
X-CYCLE on 3 (Discontinuous Alternating Nice Loop, length 8):
+3[D4]-3[D1]+3[H1]-3[J2]+3[J5]-3[A5]+3[C4]-3[D4]
- Contradiction: When D4 is set to 3 the chain implies it cannot be 3 - it can be removed
Passo 24
XY-Chain
valore: 226.8
categoria doc: XY_Chains
length=6, chain ends: D3 and F8
This proves 7 is the solution at one or possibly both ends of the chain
-7[D3]+9[D3]-9[D6]+3[D6]-3[E4]+2[E4]-2[E9]+3[E9]-3[F9]+6[F9]-6[F8]+7[F8]
- 7 can be removed from D8
- 7 can be removed from F3
Last candidate 9 in F3 changed to solution
Passo 25
Naked Singles
valore: 1.3
categoria doc: Getting_Started
Last candidate 7 in D3 changed to solution
Passo 26
Hidden Singles
valore: 2.5
categoria doc: Getting_Started
7 in F8 is last in row/column/box
Passo 27
Hidden Singles
valore: 2.4
categoria doc: Getting_Started
6 in C8 is last in column
Passo 28
Hidden Singles
valore: 2.3
categoria doc: Getting_Started
3 in A8 is last in column/box
3 in C4 is last in row
Passo 29
Naked Singles
valore: 1
categoria doc: Getting_Started
Last candidate 5 in A5 changed to solution
Last candidate 2 in E4 changed to solution
Passo 30
Naked Singles
valore: 0.9
categoria doc: Getting_Started
Last candidate 7 in A1 changed to solution
Last candidate 3 in E9 changed to solution
Passo 31
Naked Singles
valore: 0.9
categoria doc: Getting_Started
Last candidate 2 in A2 changed to solution
Last candidate 6 in F9 changed to solution
Passo 32
Naked Singles
valore: 0.8
categoria doc: Getting_Started
Last candidate 8 in F7 changed to solution
Last candidate 9 in J9 changed to solution
Passo 33
Naked Singles
valore: 0.7
categoria doc: Getting_Started
Last candidate 2 in B9 changed to solution
Last candidate 4 in D7 changed to solution
Last candidate 6 in J7 changed to solution
Passo 34
Naked Singles
valore: 0.6
categoria doc: Getting_Started
Last candidate 4 in B8 changed to solution
Last candidate 2 in D8 changed to solution
Passo 35
Hidden Singles
valore: 1.2
categoria doc: Getting_Started
4 in C2 is last in row/column/box
7 in H2 is last in row/column/box
8 in D2 is last in row/column/box
Passo 36
Pointing Pairs
valore: 15.7
categoria doc: Intersection_Removal
Pair: between Box 5 and Col 6:
- 3 can be removed from H6
Passo 37
Y-Wing
valore: 40.7
categoria doc: Y_Wing_Strategy
Y-Wing pattern. Hinge: H6 (1/9), wings D6 H1, therefore
- 3 can be removed from D1
Last candidate 5 in D1 changed to solution
Passo 38
Naked Singles
valore: 0.4
categoria doc: Getting_Started
Last candidate 9 in D4 changed to solution
Last candidate 3 in F2 changed to solution
Passo 39
Naked Singles
valore: 0.2
categoria doc: Getting_Started
Last candidate 1 in A4 changed to solution
Last candidate 3 in D6 changed to solution
Last candidate 1 in F6 changed to solution
Last candidate 1 in J2 changed to solution
Passo 40
Naked Singles
valore: 0.1
categoria doc: Getting_Started
Last candidate 9 in A7 changed to solution
Last candidate 5 in B2 changed to solution
Last candidate 9 in B5 changed to solution
Last candidate 5 in F4 changed to solution
Last candidate 3 in H1 changed to solution
Last candidate 9 in H6 changed to solution
Last candidate 3 in J5 changed to solution
Passo 41
Naked Singles
valore: 0
categoria doc: Getting_Started
Last candidate 1 in B1 changed to solution
Last candidate 1 in C7 changed to solution
Last candidate 1 in H5 changed to solution
Passo 42
Naked Singles
valore: 0
categoria doc: Getting_Started
Last candidate 9 in C1 changed to solution