Struct Variable

pub struct Variable {
    pub row: usize,
    pub col: usize,
    pub num: usize,
}

Represents a variable in the SAT encoding of a Sudoku puzzle.

A variable (row, col, num) is true if the cell at (row, col) contains num. Rows, columns, and numbers are 1-indexed.

Fields

row: usize

The row index (1-based).

col: usize

The column index (1-based).

num: usize

The number in the cell (1-based).

Implementations

impl Variable

pub const fn new(row: usize, col: usize, num: usize) -> Self

Creates a new Variable.

Arguments

• row: 1-based row index.
• col: 1-based column index.
• num: 1-based number.

pub const fn encode(&self, size: Size) -> usize

Encodes the variable into a unique positive integer for SAT solvers.

The encoding scheme maps (row, col, num) to a unique integer. Assumes row, col, num are 1-indexed and within the board’s dimensions. The resulting integer is also 1-indexed.

Formula: ((row - 1) * board_size^2) + ((col - 1) * board_size) + (num - 1) + 1

Arguments

• size: The Size of the Sudoku board.

Trait Implementations

impl Clone for Variable

fn clone(&self) -> Variable

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Variable

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for Variable

fn eq(&self, other: &Variable) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Variable

impl Eq for Variable

impl StructuralPartialEq for Variable