How to play Sudoku: step by step puzzle solution

2024 Author: Sierra Becker | [email protected]. Last modified: 2024-02-26 03:46

Sudoku is a very interesting puzzle game. It is necessary to arrange the numbers from 1 to 9 in the field in such a way that each row, column and block of 3 x 3 cells contains all the numbers, and at the same time they should not be repeated. Consider step-by-step instructions on how to play Sudoku, basic methods and a solution strategy.

Solution algorithm: from simple to complex

The algorithm for solving the Sudoku mind game is quite simple: you need to repeat the following steps until the problem is completely solved. Gradually move from the easiest steps to more difficult ones, when the first ones no longer allow you to open a cell or exclude a candidate.

Single candidates

First of all, for a more visual explanation of how to play Sudoku, let's introduce a numbering system for blocks and cells of the field. Both cells and blocks are numbered from top to bottom and from left to right.

Let's start looking at our field. First you need to find single candidates for a place in the cell. They can be hidden or explicit. Consider possible candidates for the sixth block: we see that only one of the five freecells there is a unique number, therefore, the four can be safely entered in the fourth cell. Considering this block further, we can conclude: the second cell should contain the number 8, since after the exclusion of the four, the eight in the block does not occur anywhere else. With the same justification, we put the number 5.

Next, we consider each row, column or block for the presence of hidden or explicit single candidates, taking into account the numbers entered earlier, and enter them in the field.

Carefully look through all the options. Looking at the central cell of the fifth block, we find that there can be no other options besides the number 9 - this is a clear single candidate for this cell. The nine can be crossed out from the rest of the cells of this block, after which the remaining numbers can be easily put down. Using the same method, we pass through the cells of other blocks.

How to discover hidden and explicit "naked couples"

After entering the necessary numbers in the fourth block, let's return to the empty cells of the sixth block: it is obvious that the number 6 should be in the third cell, and 9 - in the ninth.

The concept of "naked couple" is present only in the game of Sudoku. The rules for their detection are as follows: if two cells of the same block, row or column contain an identical pair of candidates (and only this pair!), then the other cells of the group cannot have them. Let's explain this on the example of the eighth block. Putting possible candidates in each cell, we find an obvious “naked pair”. Numbers 1 and 3are present in the second and fifth cells of this block, and there and there there are only 2 candidates, therefore, they can be safely excluded from the remaining cells.

Completing the puzzle

If you learned the lesson on how to play Sudoku and followed the above instructions step by step, then you should get something like this picture:

Here you can find single candidates: one in the seventh cell of the ninth block and two in the fourth cell of the third block. Try to solve the puzzle to the end. Now compare your result with the correct solution.

Did it work? Congratulations, this means that you have successfully mastered the lessons on how to play Sudoku and learned how to solve the simplest puzzles. There are many varieties of this game: Sudoku of different sizes, Sudoku with additional areas and additional conditions. The playing field can vary from 4 x 4 to 25 x 25 cells. You may come across a puzzle in which the numbers cannot be repeated in an additional area, for example, diagonally.

Start with simple options and gradually move on to more complex ones, because with practice comes experience.