Sudoku is a popular number puzzle game in which players must fill a 9x9 grid with numbers while ensuring that each column, row, and nine 3x3 subgrids contain all of the digits 1 through 9. The puzzle begins with some of the numbers already filled in, and the player's goal is to apply logic to determine where the remaining numbers should go while adhering to the rule that no number repeats in any row, column, or subgrid.
Sudoku games owe their origins to a sort of number puzzle known as "Latin Squares," which was invented in the 18th century by Swiss mathematician Leonhard Euler. Latin Squares required filling a grid with numerals so that no number appeared more than once in any row or column. Euler's work set the groundwork for the logical framework of what would ultimately become Sudoku, although it lacked the smaller 3x3 subgrids used in modern Sudoku problems.
The modern version of Sudoku, as we know it today, was first introduced in the late 1970s by an American puzzle constructor named Howard Garns. Garns created a puzzle that combined the principles of Euler’s Latin Squares with a grid divided into smaller regions (subgrids). His puzzle, originally called "Number Place," was published in 1979 in the magazine Dell Pencil Puzzles and Word Games in the United States. However, the game did not gain significant popularity at that time.
Sudoku's actual surge to prominence occurred in Japan during the mid-1980s. In 1984, Nikoli, a puzzle publisher, introduced the puzzle to Japanese audiences under the name "Sudoku," which is short for "Sūji wa dokushin ni kagiru" (meaning "the digits must remain single"). The name was easy to remember, and the game rapidly became a huge hit thanks to its simplicity and unusual challenge. Sudoku's popularity in Japan subsequently expanded internationally, and by the early 2000s, it had become a global phenomenon, appearing in newspapers, books, and internet platforms all over the world.
Sudoku is a game in which you fill a 9x9 grid with numbers so that each row, column, and nine 3x3 subgrids contain all of the digits from 1 to 9, without repetition. The puzzle starts with some numbers already filled in, and the goal is to use logic to identify the proper arrangement of the remaining digits. The basics are straightforward, but the method might get complicated depending on the difficulty of the challenge.
To begin, search over the grid for half filled rows, columns, or subgrids. Begin by focusing on these regions and then using the elimination process to identify where the missing numbers should go. For example, if a row already has the numbers 1, 2, 4, and 7, you know that the remaining numbers (3, 5, 6, 8, 9) must be filled in the blank cells. Columns and subgrids follow the same reasoning. The possible positions for the missing numbers can be narrowed down by carefully evaluating the numbers previously put.
As you fill in more numbers, the problem grows easier since each new location adds new hints to the remaining cells. A fundamental method is to keep track of potential candidates for each cell using pencil markings (little numbers written in the cells). This helps to eliminate confusion and makes it easier to identify trends that lead to appropriate placements.
Patience and attention to detail are crucial when playing Sudoku. It's important to avoid guessing, as even a small mistake can snowball and ruin the entire puzzle. The best approach is to move systematically through the grid, constantly cross-referencing rows, columns, and subgrids to find the most logical placements for each number. Once the entire grid is filled with the numbers 1 through 9 in each section, you've successfully completed the puzzle.