Oct 25 - Super Hard
Puzzle Copyright © Kevin Stone
Share link – www.brainbashers.com
Reasoning
R1C4 can only be <1>
R4C6 can only be <4>
R6C4 can only be <2>
R9C6 can only be <8>
R6C1 can only be <8>
R4C4 can only be <6>
R1C6 can only be <3>
R8C5 can only be <4>
R6C6 can only be <1>
R9C4 can only be <7>
R5C5 can only be <3>
R6C9 can only be <3>
R9C5 can only be <6>
R1C9 is the only square in row 1 that can be <7>
R3C3 is the only square in row 3 that can be <3>
R3C8 is the only square in row 3 that can be <6>
R5C1 is the only square in row 5 that can be <6>
R7C2 is the only square in row 7 that can be <4>
R7C8 is the only square in row 7 that can be <9>
R9C1 is the only square in row 9 that can be <3>
R8C7 is the only square in row 8 that can be <3>
R9C9 is the only square in row 9 that can be <4>
Intersection of column 2 with block 1. The value <8> only appears in one or more of squares R1C2, R2C2 and R3C2 of column 2. These squares are the ones that intersect with block 1. Thus, the other (non-intersecting) squares of block 1 cannot contain this value.
R2C3 - removing <8> from <258> leaving <25>
Intersection of column 7 with block 3. The value <1> only appears in one or more of squares R1C7, R2C7 and R3C7 of column 7. These squares are the ones that intersect with block 3. Thus, the other (non-intersecting) squares of block 3 cannot contain this value.
R2C9 - removing <1> from <1258> leaving <258>
Squares R2C3 and R7C3 in column 3 and R2C7 and R7C7 in column 7 form a Simple X-Wing pattern on possibility <2>. All other instances of this possibility in rows 2 and 7 can be removed.
R2C1 - removing <2> from <1259> leaving <159>
R2C9 - removing <2> from <258> leaving <58>
Intersection of column 9 with block 6. The value <2> only appears in one or more of squares R4C9, R5C9 and R6C9 of column 9. These squares are the ones that intersect with block 6. Thus, the other (non-intersecting) squares of block 6 cannot contain this value.
R5C8 - removing <2> from <125> leaving <15>
Squares R1C2 and R5C2 in column 2 and R1C8 and R5C8 in column 8 form a Simple X-Wing pattern on possibility <5>. All other instances of this possibility in rows 1 and 5 can be removed.
R1C1 - removing <5> from <259> leaving <29>
R5C9 - removing <5> from <125> leaving <12>
Squares R5C2 (XY), R9C2 (XZ) and R5C8 (YZ) form an XY-Wing pattern on <1>. All squares that are buddies of both the XZ and YZ squares cannot be <1>.
R9C8 - removing <1> from <12> leaving <2>
R9C2 can only be <1>
R1C8 can only be <5>
R7C7 can only be <8>
R5C8 can only be <1>
R2C9 can only be <8>
R2C5 can only be <9>
R8C9 can only be <1>
R3C7 can only be <1>
R3C2 can only be <8>
R2C7 can only be <2>
R5C9 can only be <2>
R5C2 can only be <5>
R4C9 can only be <5>
R7C3 can only be <2>
R8C1 can only be <5>
R1C5 can only be <8>
R2C3 can only be <5>
R1C2 can only be <2>
R4C1 can only be <2>
R8C3 can only be <8>
R2C1 can only be <1>
R1C1 can only be <9>
Today's Sudoku Puzzles
All daily items change at midnight GMT – set your local time zone.
Note: BrainBashers has a Dark Mode setting.