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Sudoku may help to develop deductive reasoning. It is a kind of logical thinking process. Deductive reasoning skills may help people to solve problems at work or in other areas of life. Sudoku is one of the most popular classic games in the world. Several million people solve this puzzle daily! This is not surprising as playing Sudoku may have a lot of benefits. Sudoku is a number puzzle that will get you hooked, may train your brain, develop logical thinking and help you to relax after a hard day. If you play Sudoku daily, you may soon notice improvements in your memory, and concentration. Therefore, it will be useful to add Sudoku to your daily routine!
When Sudoku-mania swept the globe in the mid-2000s, many mathematicians, programmers and computer scientists – amateur and professional – started to investigate Sudoku itself. They were less interested in solving individual puzzles, and more focused on asking and answering mathematical and/or computational questions about the entire universe of Sudoku puzzles and solutions.Unique sudoku boards, I call them UBs, number 5,472,730,538 which is reduced from the actual larger number because of rotating and symmetry. So if the UBs are computer filed, then a (unique solution) puzzle can be solved by matching it's clues with a UB. Kind of like the lotto system for seeing if anyone won the lotto. 2 or more (millions? billions? more) sudoku puzzles can have the same UB. I made 2 sudokus in a matter of minutes, using the same UB, and each of course then has the same solution. But one is rated diabolical and has 24 clues and the other is rated extreme and has 23 clues. Puzzles with 20 clues on a single UB board can be arranged in 81 nCr 20 ways which is 4.69E18. Many of these puzzles would not have single solutions and would be invalid. On the average, if 1 out of a 1000 is valid then that is still 4.69E15 20 clue puzzles for 1 UB. Multiply that by how many UBs there are and that = about 5E24 20 clue puzzles. Now to save time and avoid tedious addition we multiply that by 15 to cover the other clue numbered puzzles arbitrarily (17 to 32). Very roughly, the number of sudoku puzzles is about 7.5E25.
Other people started to send me their 17-clue puzzles and I added any new ones to the list until, after a few years, I had collected more than 49,000 different 17-clue Sudoku puzzles. Playing sudoku evil online has a lot of advantages. While solving sudoku, your brain exercises logic, learns to make decisions, and puts your memory to the test. Regularly playing evil sudoku is a good method of improving your concentration. Play 1 or 2 evil sudoku games every day and you will not have any problems with losing focus while doing important things. Make sure the sum of numbers in each cage is equal to the number in the upper left corner of the cage.Even though evil sudoku is an extremely difficult game level, many experienced players find it the best way for brain training and developing mental skills. How to solve Sudoku Evil?
Tip 1: Look for rows, columns of 3×3 sections that contain 5 or more numbers. Work through the remaining empty cells, trying the numbers that have not been used. In many cases, you will find numbers that can only be placed in one position considering the other numbers that are already in its row, column, and 3×3 grid.An “unavoidable set” in a completed Sudoku grid is a subset of the clues whose entries can be rearranged to leave another valid completed Sudoku grid. For a puzzle to be uniquely completable, it must contain at least one entry from every unavoidable set. As a mathematician specialising in the area of combinatorics (which can very loosely be defined as the mathematics of counting configurations and patterns), I was drawn to combinatorial questions about Sudoku.