For more difficult puzzles see my collection of printable free sudoku puzzles. You will be able to solve the puzzle quickly now.Ĭongratulations on solving a very difficult Sudoku puzzle. It starts with solving the row and column that contain the most numbers. The swordfish strategy can be used on any sudoku puzzle, but it’s most effective on puzzles that are partially completed. Solve the naked single and the logjam is broken. There are a lot of ways to solve a sudoku puzzle, and some work better than others. Here we outline the basic strategies and then. The third is to consider the total value of a region.
The second is to consider the different ways that a sum can be created. The first is to use the strategies for solving regular sudoku puzzles. When you remove the 4s, you now expose a naked single in (R7,C7). There are three basic methods used to solving killer sudoku puzzles. The cells circled in red may have the number 4 removed from them safely. Therefore it is safe to eliminate the 4s from column 3 and column 7 except for the highlighted positions. We do know that it must reside in two of the four positions highlighted. At this point we do not know which pair the 4 will reside in. Sudoku rules forbid any other combination. This means the 4 will reside in the pair (R2,C3) and (R5,C7) or in the pair (R2,C7) and (R5,C3). The two positions have to be diagonally opposites forming an X. The number 4 can only appear in two of the four positions. These four positions are highlighted in grey. In row 5 the cells are (R5,C3), and (R5,C7). In row 2 the cells are (R2,C3) and (R2,C7). Each row has the number 4 in only two cells. In the example shown, an X Wing pattern occurs in row 2 and row 5. This candidate must reside in both rows and share the same two columns or vice versa. 1) Know where to start solving 2) Look for single candidates 3) Work on your scanning techniques 4) Dont focus too long in the one place 5) Keep the. If these terms are not familiar, read my article Sudoku Tips for an illustrative guide.Īn X-Wing pattern occurs when two rows (or two columns) each contain only two cells that hold a matching candidate. You will need to solve naked singles, hidden singles, a naked pair (4,7) in row 7, a locked candidate (5) in column 7, and a naked triple (2,4,5) in column 1 first. To understand 'Pointing pairs' better, let's take a look. So, you can eliminate this Note from any other cells in the row or column. This means that the Note must be the solution for one of the two cells in the block. If you have trouble getting to this position, follow the steps I have outlined in my article “How to Solve Sudoku” X-Wing”. 'Pointing pairs' applies when a Note is present twice in a block and this Note also belongs to the same row or column. It is found in newspapers, on websites, in pocket-sized books and in handheld PDAs. You will need to partially solve the puzzle to reach the picture shown. Sudoku is the addictive logic game that was developed in Japan in the 1980s and 90s, and then became a worldwide phenomenon after being introduced to the English-speaking world by the London Times in 2004.
SUDOKU STRATEGY PDF
Go ahead download and print out this PDF very hard Sudoku puzzle #1. and follow along. Read about my strategies below and then share yours. Sudoku strategies begin with knowing where to start, what to look for, and applying logic. Use proper English and sentence structure. Those with experience solving Sudoku puzzles know that there are two important strategies that we can use to make progress towards filling in all the. We will use 0 as our empty cell.In this article, I use one of my handcrafted very difficult puzzles that has a known X-Wing pattern. Do you have a great Sudoku strategy Share it Write a 300 word article that explains your strategy. A cell that only has one possible entry should be filled in.
Sudoku is a strategy game that necessitates the development of skills. As a first step in resolving a Sudoku puzzle, jot down in each empty cell any possible entry in that cell that won’t negatively impact the One Rule. While most modern definitions state that a Sudoku puzzle has to have only one answer, a few people claim. There is a bit of a disagreement in the Sudoku community on this. What are the solving strategies for arrow sudoku When solving arrow sudokus, it can be particularly useful (in a 9x9 puzzle) to see if there are any 9s. While every problem has a solution, not everyone can solve it. This method is actually a bit controversial, because the logic it uses assumes the fact that the Sudoku puzzle you are working on has only one unique answer. It could provide you with the unique outlook you require to complete the puzzle successfully. If you have to start over, use a new strategy you haven’t tried before. First of all, let's define our board as a two-dimensional array of integers. Sudoku Y-Wing Strategy that always works.