Sudoku

Sudoku is a high-fidelity digital implementation of the classic deductive reasoning puzzle. The technical core is based on "Constraint Satisfaction," requiring players to populate a 9x9 grid so that every digit from 1-9 appears exactly once in every row, column, and 3x3 subgrid. It features real-time error checking and note-taking systems, making it an essential tool for logic purists who want to practice advanced deduction strategies in a clean, distraction-free environment.

Your goal is to fill the empty cells of a 9x9 matrix with digits. Each horizontal row, vertical column, and 3x3 sub-square must contain all numbers from 1 to 9 without any repetition. Tap a cell and select a number from the interface. Use the "Note Mode" to pencil in multiple candidates for a single cell. The game provides real-time feedback on conflicts; if a move violates a logic rule, the cell will highlight in red. Success is measured by the speed and accuracy of the grid's completion.

Solving at a Master level depends on "Candidate Elimination Logic." Instead of searching for where a number can go, look for where it must go. Utilize the "Naked Pair" technique: if two cells in a block can only contain the same two numbers, you can eliminate those numbers from all other cells in that block. A pro strategy is to identify "Locked Candidates"—situations where a number in a row also belongs to a specific 3x3 subgrid, allowing you to clear potential spots in adjacent columns.