Sudoku Programming with C

CHAPTER 18

Multi-Grid Sudokus

You obtain a multi-grid Sudoku when you combine two or more classic puzzles by partially overlapping them. For example, Figure 18-1 shows a double Sudoku.

Figure 18-1. A double Sudoku

You solve a double Sudoku by solving the two 9x9 puzzles normally, but whenever you solve one of the cells grayed in Figure 18-1, that solution is valid for both puzzles.

There Are Many Different Multi-Grid Sudokus

To explore the way in which you can combine several Sudoku grids to form composite puzzles, let’s reduce multi-grid Sudokus ...