Sudoku

Sudoku is a popular number puzzle game that challenges players to use logic and deduction to fill a 9x9 grid with digits. The grid is divided into 9 smaller 3x3 subgrids, and some of the cells are pre-filled with numbers. The objective is to complete the grid following these simple rules: 1. **Each row** must contain the numbers 1 through 9, with no repetition. 2. **Each column** must also contain the numbers 1 through 9, with no repetition. 3. **Each 3x3 subgrid** (also called a "box") must contain the numbers 1 through 9, with no repetition. The puzzle starts with some numbers already filled in (called "clues"), and the player must deduce the correct numbers for the remaining empty cells using logic alone. 4x4 grid puzzle is also having same logic and rules, only difference is that the numbers need to be fill from 1 to 4. Sudoku puzzles come in various levels of difficulty, from easy to extremely challenging, depending on the number and distribution of the pre-filled clues. The game requires no arithmetic, just logical reasoning and pattern recognition. It is popular as both a recreational activity and a mental exercise. **Sudoku** originated from the concept of **Latin squares**, which date back to the 18th century, but the modern form of the puzzle was developed in 1979 by American puzzle constructor **Howard Garns**. Initially called **"Number Place"**, it was published in *Dell Pencil Puzzles and Word Games* magazine. The puzzle gained significant popularity in **Japan** in the 1980s, where it was renamed **"Sudoku"** (meaning "single number" in Japanese) by the puzzle company **Nikoli**. They refined the game, focusing on pure logic rather than trial and error, which helped define the format we know today. Sudoku became a global sensation in the early 2000s, particularly after **Wayne Gould** introduced it to *The Times* newspaper in 2004. From there, its popularity skyrocketed, leading to widespread availability in newspapers, books, apps, and websites. Today, Sudoku is one of the most recognized and widely played puzzles worldwide. IGRS Rating: 3+