What does yellow mean in Sudoku?

If cells in yellow identified the solution then candidate 2 would be the solution in two cells of Row "D", which is not possible. Hence no candidates colored in yellow can be the solution in their respective cells. If the yellow state is not the solution, then the green state is the solution.

What do colors mean in Sudoku?

Colors are used to indicate the opposing sides of conjugate pairs to allow potential candidate removal to be identified. A chain of conjugate pairs exists when multiple conjugate pairs are linked together.

How do you solve Sudoku with colors?

* Each color must appear exactly once in every row, column and 3x3 square. * A color cannot go into any cell if the same color already appears in that row, column or square. * Diagonal lines don't count - you need to pay attention only to the 3x3 squares, the horizontal rows and the vertical columns.

What is the secret to figuring out Sudoku?

The most basic strategy to solve a Sudoku puzzle is to first write down, in each empty cell, all possible entries that will not contradict the One Rule with respect to the given cells. If a cell ends up having only one possible entry, it is a "forced" entry that you should fill in.

What do the GREY squares in Sudoku mean?

Odd. Place a digit from 1 to 9 into each of the empty squares so that each digit appears exactly once in each of the rows, columns and the nine outlined 3x3 regions. The grey squares must contain odd digits. Sudoku. Solution.

How to Play Sudoku for Absolute Beginners

How do you know if a Sudoku is unsolvable?

Solvable A sudoku puzzle is solvable if there is only one way to fill in a sudoku board to make it valid. Cell A cell is a position on the Sudoku board. Cells contain cell values and pencil-marks (denoted by (n, {a, b, ..., j}) with n the value of the cell and {a, b, ..., j} the set of pencil-marks).

What does blue mean on Sudoku?

The unsolved puzzle showed only the givens (the numbers in black). The numbers in blue represent the solution. As can be seen in the picture, every one of the 9 rows of the grid contains all numbers from 1 to 9 and, of course, no number is repeated. The same can be said for every column, and every box.

What are the 3 rules of Sudoku?

Is Sudoku good for the brain?

Sudoku keeps your brain active and reduces the risk of Alzheimer's, a most common cause of dementia that affects a person's thinking and behavioural skills. Stimulates your mind: The game works on your logical thinking process as you are absorbed in solving a puzzle and eventually improve your number skills.

What is the 45 rule in Sudoku?

The 45 rule is a basic solving-technique in Killer Sudoku. Each house (row, column, nonet) must add to 45 (the sum of the digits 1 through 9).

Can there be 2 solutions to a Sudoku puzzle?

A well-formed Sudoku puzzle is one that has a unique solution. A Sudoku puzzle can have more than one solution, but in this case the kind of logical reasoning we described while discussing solving strategies may fall short.

Is there a solution to every Sudoku puzzle?

Realistically, no! There are 6,670,903,752,021,072,936,960 possible solvable Sudoku grids that yield a unique result (that's 6 sextillion, 670 quintillion, 903 quadrillion, 752 trillion, 21 billion, 72 million, 936 thousand, 960 in case you were wondering). That's way more than the number of stars in the universe.

What is an evil Sudoku puzzle?

What is Sudoku Evil? Sudoku evil is a 9×9 grid sudoku puzzle with the highest possible level of difficulty. It's an advanced level only for experienced sudoku solvers.

What is the magic number in Sudoku?

Now Gary McGuire, a mathematician at University College Dublin, has come up with what he says is a proof that finds the minimum number of clues, or starting digits, needed to complete the game is 17.

Is there math in Sudoku?

Myth: You must be good at math to play Sudoku

But this is not true. Sudoku is not about adding or subtracting or doing arithmetic – it's about placing numbers 1-9 on a grid, without repeating any of the same numbers within the same row, column or square. Sudoku is not a “math” game, it's a logic game.

Do Sudoku players have high IQ?

From this case study it can be concluded that an individual who is skilled at solving Sudoku puzzles likely has a high general IQ. The results of the weak correlation between Sudoku scores and the WAIT test indicates that in some cases a high Sudoku doesn't necessarily mean a high general IQ.

What is the average time to complete Sudoku?

It is believed that the average Sudoku player spends approximately 20 minutes solving a typical Sudoku puzzle. For very hard puzzles, that number can be much higher. While the game itself can be challenging and complex, several strategies can be used successfully to find the solution.

Does Sudoku fight dementia?

“Just sitting down and doing Sudoku isn't probably going to be the one key thing that's going to prevent you from developing Alzheimer's disease,” she said. Moreover, doing only one type of puzzle or another is not the key either. The brain needs to be exercised, just like any other muscle in the body.

How do you solve a hard Sudoku without guessing?

What does R and C mean in Sudoku?

A single cell is called out by specifying its row and column numbers with an 'r' preceding the row number and a 'c' preceding the column number. Examples: r1c9 means the cell in row one and column nine (the rightmost cell on the top row). r8c3 is the cell on row eight, third cell from the left.

What are the 2 dots in Sudoku?

Normal sudoku rules apply. White dots between two cells indicate consecutive digits and black dots between two cells indicate a ratio of 1:2.

Why can't I figure out Sudoku?

Whatever the reason, many Sudoku beginners are making a mistake, because they're not spending enough time looking at squares. Squares (there are 9 of them on the grid, and each contains 9 spaces) are a great place to look for opportunities to place numbers, because each square is made up of other rows and columns.

Can Sudoku have negative numbers?

To solve this Sudoku, you must place digits from 1 to 9, but be aware that there exists also negative numbers! So, like standard Sudoku, each of the rows, columns and 3x3 boxes contains exact one of the 1 - 9 values in their absolute value.