Solve Method "Line / Column / Block"

For a comprehensive reading, please refer to Sudoku Grid definitions.

The principle of Sudoku is that in each line, column and block, a number between 1 and 9 could only be used one time. At crossing of line, columns or block,  value of the cell are limited. By looking at each cell systematically (roughly) or by identifying the promising cells, it's easy to find the missing number.

This simple method may allow to solve an easy grid. It is selected by default by Sudoku1 automatic solve methods.

Here are some simple examples.

Example 1 : In a line, if there is only one empty cell, value is immediately identified.

Number 8 is the only one possible for this cell. All others are used in the line.

Example 2 : In a column, if there is only one empty cell, value is immediately identified.

 Number 6 is the only one possible for this cell. All others are used in the column.

Example 3 : In a block, if there is only one empty cell, value is immediately identified.

Number 2 is the only one possible for this cell. All others are used in the block.

Example 4 : At crossing of a line, column and/or block, if there is only one possible value, value is immediately identified.

Number 5 is the only one possible for this cell. Numbers 1,2,3,4,6 are used in the line; Numbers 8,9 are used in the column; Number 7 is used in the block.