Struct QUBOProblem 

pub struct QUBOProblem {
    pub num_variables: usize,
    pub variable_names: Vec<String>,
    pub quadratic: Array2<f64>,
    pub linear: Array1<f64>,
    pub offset: f64,
}

A Quadratic Unconstrained Binary Optimization (QUBO) problem.

QUBO represents the optimization problem: minimize x^T Q x + c^T x

where x ∈ {0, 1}^n is a binary vector.

Fields

num_variables: usize

Number of binary variables

variable_names: Vec<String>

Variable names for reference

quadratic: Array2<f64>

Quadratic coefficients matrix Q (upper triangular)

linear: Array1<f64>

Linear coefficients c

offset: f64

Constant offset

Implementations

impl QUBOProblem

pub fn new(num_variables: usize) -> Self

Create a new QUBO problem with given number of variables.

pub fn with_names(variable_names: Vec<String>) -> Self

Create a QUBO problem with named variables.

pub fn set_linear(&mut self, i: usize, value: f64)

Set a linear coefficient.

pub fn set_quadratic(&mut self, i: usize, j: usize, value: f64)

Set a quadratic coefficient (ensures upper triangular).

pub fn add_linear(&mut self, i: usize, value: f64)

Add to a linear coefficient.

pub fn add_quadratic(&mut self, i: usize, j: usize, value: f64)

Add to a quadratic coefficient.

pub fn evaluate(&self, assignment: &[usize]) -> f64

Evaluate the QUBO objective for a binary assignment.

pub fn to_ising(&self) -> IsingModel

Convert QUBO to Ising model (h, J).

The Ising model is: H = Σᵢ hᵢ σᵢ + Σᵢⱼ Jᵢⱼ σᵢσⱼ where σ ∈ {-1, +1}.

The transformation is: x = (1 + σ) / 2

pub fn variable_index(&self, name: &str) -> Option<usize>

Get the index of a variable by name.

Trait Implementations

impl Clone for QUBOProblem

fn clone(&self) -> QUBOProblem

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for QUBOProblem

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for QUBOProblem

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for QUBOProblem

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.