Struct IntegerKnapsack 

pub struct IntegerKnapsack { /* private fields */ }

The Integer Knapsack problem.

Given n items, each with positive size s_i and positive value v_i, and a nonnegative capacity B, find non-negative integer multiplicities c_0, ..., c_{n-1} such that sum c_i * s_i <= B, maximizing sum c_i * v_i.

Representation

Variable i has domain {0, ..., floor(B / s_i)} representing the multiplicity of item i.

Example

use problemreductions::models::set::IntegerKnapsack;
use problemreductions::{Problem, Solver, BruteForce};

let problem = IntegerKnapsack::new(vec![3, 4, 5, 2, 7], vec![4, 5, 7, 3, 9], 15);
let solver = BruteForce::new();
let solution = solver.find_witness(&problem);
assert!(solution.is_some());

Implementations

impl IntegerKnapsack

pub fn new(sizes: Vec<i64>, values: Vec<i64>, capacity: i64) -> Self

Create a new IntegerKnapsack instance.

Panics

Panics if sizes and values have different lengths, or if any size or value is not positive, or if capacity is negative.

pub fn sizes(&self) -> &[i64]

Returns the item sizes.

pub fn values(&self) -> &[i64]

Returns the item values.

pub fn capacity(&self) -> i64

Returns the knapsack capacity.

pub fn num_items(&self) -> usize

Returns the number of items.

Trait Implementations

impl Clone for IntegerKnapsack

fn clone(&self) -> IntegerKnapsack

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for IntegerKnapsack

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for IntegerKnapsack

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Problem for IntegerKnapsack

const NAME: &'static str = "IntegerKnapsack"

Base name of this problem type (e.g., “MaximumIndependentSet”).

type Value = Max<i64>

The evaluation value type.

fn variant() -> Vec<(&'static str, &'static str)>

Returns variant attributes derived from type parameters.

fn dims(&self) -> Vec<usize>

Configuration space dimensions. Each entry is the cardinality of that variable.

fn evaluate(&self, config: &[usize]) -> Max<i64>

Evaluate the problem on a configuration.

fn num_variables(&self) -> usize

Number of variables (derived from dims).

fn problem_type() -> ProblemType

Look up this problem’s catalog entry.

impl ReduceTo<ILP<i32>> for IntegerKnapsack

type Result = ReductionIntegerKnapsackToILP

The reduction result type.

fn reduce_to(&self) -> Self::Result

Reduce this problem to the target problem type.

impl Serialize for IntegerKnapsack

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl DeclaredVariant for IntegerKnapsack