Sudoku being a number-placing puzzle is also an excellent brain game. There is no specific formula for how to play Sudoku. Every Sudoku has a unique solution.
The origin and meaning of the name of this famous number puzzle are worth mentioning. The name of this puzzle, “SUDOKU” is the abbreviation from the Japanese words, “suji was dokushin ni kagiru” which translates into English as “the numbers (or digits) always must remain single.” This being a basic rule of this awesome game.
The simplest way how to play Sudoku is the scanning technique. It involves scanning rows and columns inside each triple-box area, ruling out numbers or squares to find situations where only a single name fits into a single square. This process is usually fast enough to solve any sudoku puzzles until the end.
If you are solving Sudoku on paper and you are a new player, use a pencil instead of a pen. This ensures, if you make mistakes you can erase them out quickly.
Below instructions will impact your methods, tricks, tips to finish a Sudoku puzzle easily. This would be true for a beginner in this game also.
Let us start with the necessary steps and proceed to the more complex.
Step 1: Solving a Sudoku puzzle
The game Sudoku is to fill nine x nine grids so that each column, each row, and each of the nine three x three squares (also named blocks or regions) contain numbers from one to nine. Each pointed number can very well appear once in a row, column or square. The total of the numbers in a single area has to be equal to the clue in the area’s top-left corner.
A cell is the smallest square in Sudoku. A row, column, and region are made up of nine cells, and the entire grid has eighty-one cells. An area is surrounded by lines that are thicker, making it easier to play this game.
Step 2: The Basic Scanning
A quick way to solve squares can be done by you just scanning the Sodoku grid by which you almost always find a square that can be resolved.
Scanning process involves two steps, they are
- A) Cross-hatching.
- B) Counting.
1) Cross-hatching. Scan rows and columns to rule out where a specific number can be in a given region.
2) Counting. In counting you count all the different numbers that are in a row, column and region that connects to one cell. When there is just one number missing, then that is what should be in the cell.
Step 3: A higher level method, The Analysis
The Analysis method involves candidate elimination. This is applicable when the pair of numbers is the only possible answer to two cells. Candidate elimination can also be used with three figures in three compartments.
However, one must first scan (Step 2), before analyzing (Step 3.)
More advanced solving techniques:-
The x-wing technique
Basically, in this technique, there are only two possible ways of placing two numbers in four squares forming a rectangle. There is a relationship between the diagonally opposite squares, thus the “x” in x-wing. The term x-wing gets derived from the x-wing fighters in movie Star Wars.
The Swordfish technique
This is one of the most complicated methods for Sudoku. The Swordfish is similar to X-wing, with three rows and columns instead of two. A swordfish is formed when for three rows, there are two or three possible squares in which a particular number can be placed, and for all three rows, these squares lie in the same three columns. In this case, this specific number can be eliminated as a possibility for all other squares in those three columns. Of course, you can exchange rows and columns here.
Sudoku puzzles usually have only one solution. Sudoku’s having more than one solution might be a mistake. However, puzzles with incomplete clues can have more than one solution. According to Wikipedia, a puzzle with no clues has 6,670,903,752,021,072,936,960 solutions.
All Sudoku puzzles that are ’proper’ will have only one solution and it can be solved without guessing. Only when a Sudoku puzzle is ‘improper,’ it may have more than one possible solution. Thus in this case guessing might not help at all in solving the puzzle.
In exceptional situations, if you get stuck in a Sudoku, take a break. After returning to the puzzle usually, you find your mistake easily.
Happy solving Sudoku puzzles!