Repeated Possibility Reduction

In this level of reduction,In a block if two cells have the same set of possible values (i.e) if the values are repeated among the cells. Then those possible values can't be present in the possibilities of any other cells of that block.

Note : The above concept is also applicable in the case of n cells with n number of possibilities

An illustration for the above concept.

In this block,two cells have the same set of possible values {2,5}. Therefore these values should be removed from the possible values for other cells in that block.

In case of n cells with n possibilities.

In this case, the block is having the values {2,7,9} {7,9} and {2,9} in three cells repeatedly.Therefore these values can't be there in possible values of other cells in the block.

Figure: A Rectangular-Block from 9x9 sudoku.

Algorithm Links

• Reducing Block Possibilities
• Finding Unique Possibilities
• Block Overlap Reduction
• Repeated Possibility Reduction
• Combined Possibility Reduction
• Apply Possibility Reduction

Consecutive Sudoku Algorithms

• Apply Consecutive Constraint
• Consecutive Chain Min-Max Reduction
• Consecutive Chain Neighbor Reduction

Greater Sudoku Algorithms

• Apply Greater Sudoku Constraint
• Greater Sudoku Neighbor Reduction
• Greater Sudoku Graph Reduction