Apply Consecutive Constraint

In Consecutive Sudoku, consider two cells cell1 and cell2. If the consecutive values that are possible for the cell1 doesn't contains value 'x', then the value 'x' is removed from the possibilities of cell2 . Since there is no chance for that value to be assigned for cell2.

An illustration for the above concept.

In this Rectangular block, the cell2 (0,1) is consecutive to cell1 (0,2). The possible values available in the cell1 is {1,2,3,5,7}. The values that are consecutive to these possible values are {1,2,3,4,6,8} ie for 1 -> {2}, 2 -> {1,3}, 3 -> {2,4}, 5 -> {4,6}, 7 -> {6,8}.

Since the values 5 and 7 are not present in the consecutive values of cell1, there is no chance for the cell2 to be assigned with the values 5 and 7. Therefore the values 5 and 7 are removed from the possibilities of cell2.

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