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#Strategies for solving sudoku windows

#Strategies for solving sudoku windows

It is available on most platforms: PC, Mac, iPhone, iPad, Android, Google Play Store, Windows Phone, Amazon Appstore, Blackberry and more! You can also play Sudoku on Facebook. Sudoku Epic supports four game modes: regular Sudoku, Mini-Sudoku, Wordoku and Killer Sudoku. Using this knowledge, one can attempt the easiest technique: identifying a unique number to go in each block in the grid. As you know, the numbers from 1 to 9 must be placed once in every block. The majority of puzzles can be solved using just one key technique. For an in depth look check out this Sudoku solving tips page. All correctly formed Sudoku puzzles are solvable using logical solving techniques. You now know enough to start solving sudoku puzzles! But you may want to learn more about the different strategies involved in solving harder puzzles. The small numbers indicate "notes" made by the player. The player has determined that only the numbers 1, 4, 5 or 8 can be placed in that cell, and has thus put these numbers in as temporary notes. For example, look at the very last cell (the lower, right). The image below shows these notes, indicated by the small numbers. It is typical to use notes (also called mark-ups) to plot in possible numbers. Notice that every row, column and 3x3 region contain every number from 1-9 exactly once. For example, look at the above puzzle and compare it to the solved version below.

The goal of sudoku is simple: fill in the numbers 1-9 exactly once in every row, column, and 3x3 region. This is a typical sudoku puzzle as it is presented to the player.

Complex strategies must be utilized in order to solve the hardest puzzles.

Sudoku is not a math game, but is rather about identifying logical patterns.

Puzzles have a unique solution that can be arrived at using pure logic.

Sudoku puzzles vary in difficulty from simple to devious.

For an outside square, the solution is always the outside total – 45.The enormous popularity of sudoku across the world is due to a couple of simple facts: In general, to use the 45 rule, look for a row, column or block where all cages except one lie completely inside.įor an inside square, the solution is always 45 – the inside total. In the case, it was easier to calculate the inside total, but if the cage lying partly outside has one square outside and more than one square inside, the outside total should be used to calculate the outside square. This could also have been solved another way, by finding the 'outside' total - the total of all cages within the column, including the one lying partly outside.Īgain, as all the squares within the column must add up to 45, the 'outside' square is 54 – 45 = 9. The 14 cage can now be completed by solving the other square as a 9. Now, as the whole column must add up to 45, the ninth square (the 'inside' square in this case as it is inside the column) must be 45 – 40 = 5. In particular, we give a simple character- ization of this class, using a well-known graph theorem, and show further how the ability of this set of strategies to solve a Sudoku puzzle also implies that the solution can be represented as the unique nonnegative solution to a system of linear equations.

The numbers in this column will add up to 45.Īdditionally, because the first four cages in this column (the 15 cage, the two 9 cages and the 7 cage) lie completely within the column, the numbers in the first eight squares total 15 + 9 + 9 + 7 = 40.Ĭall this the 'inside total', because it is the total of all cages which lie completely inside the column.

Take the first column of the Killer Sudoku shown in Figure 1. Therefore, the total of all numbers in one row, column or block will always be 45. This uses the fact that every row, column and block must contain each of the numbers 1 to 9 once. The 45 RuleĪn essential Killer Sudoku solving technique is the "45 rule". You will need new specialised Killer Sudoku solving techniques to progress in these puzzles besides the standard Sudoku techniques you will already know. Killer Sudoku adds a new dimension to standard Sudoku, requiring arithmetic to solve.