quantrs2_tytan/sampler/hardware/
dwave.rs

1//! D-Wave Quantum Annealer Sampler Implementation
2
3use scirs2_core::ndarray::{Array, Ix2};
4use scirs2_core::random::{thread_rng, Rng};
5use std::collections::HashMap;
6
7use quantrs2_anneal::QuboModel;
8
9use super::super::{SampleResult, Sampler, SamplerError, SamplerResult};
10
11/// D-Wave Quantum Annealer Sampler
12///
13/// This sampler connects to D-Wave's quantum annealing hardware
14/// to solve QUBO problems. It requires an API key and Internet access.
15pub struct DWaveSampler {
16    /// D-Wave API key
17    #[allow(dead_code)]
18    api_key: String,
19}
20
21impl DWaveSampler {
22    /// Create a new D-Wave sampler
23    ///
24    /// # Arguments
25    ///
26    /// * `api_key` - The D-Wave API key
27    #[must_use]
28    pub fn new(api_key: &str) -> Self {
29        Self {
30            api_key: api_key.to_string(),
31        }
32    }
33}
34
35impl Sampler for DWaveSampler {
36    fn run_qubo(
37        &self,
38        qubo: &(Array<f64, Ix2>, HashMap<String, usize>),
39        shots: usize,
40    ) -> SamplerResult<Vec<SampleResult>> {
41        // Extract matrix and variable mapping
42        let (matrix, var_map) = qubo;
43
44        // Get the problem dimension
45        let n_vars = var_map.len();
46
47        // Map from indices back to variable names
48        let idx_to_var: HashMap<usize, String> = var_map
49            .iter()
50            .map(|(var, &idx)| (idx, var.clone()))
51            .collect();
52
53        // Convert ndarray to a QuboModel
54        let mut qubo_model = QuboModel::new(n_vars);
55
56        // Set linear and quadratic terms
57        for i in 0..n_vars {
58            if matrix[[i, i]] != 0.0 {
59                qubo_model.set_linear(i, matrix[[i, i]])?;
60            }
61
62            for j in (i + 1)..n_vars {
63                if matrix[[i, j]] != 0.0 {
64                    qubo_model.set_quadratic(i, j, matrix[[i, j]])?;
65                }
66            }
67        }
68
69        // Initialize the D-Wave client
70        #[cfg(feature = "dwave")]
71        {
72            use quantrs2_anneal::dwave::DWaveClient;
73
74            // Create D-Wave client
75            let dwave_client = DWaveClient::new(&self.api_key, None)?;
76
77            // For now, return a placeholder result since DWave API is not fully implemented
78            // TODO: Implement proper DWave integration when API is ready
79            let _dwave_result = "placeholder";
80
81            // Convert to our result format - placeholder implementation
82            let mut results = Vec::new();
83
84            // Create a simple random solution as placeholder
85            let mut rng = thread_rng();
86
87            for _ in 0..shots.min(10) {
88                let assignments: HashMap<String, bool> = idx_to_var
89                    .values()
90                    .map(|name| (name.clone(), rng.gen::<bool>()))
91                    .collect();
92
93                // Calculate placeholder energy (random for now)
94                let mut energy = rng.gen_range(-10.0..10.0);
95
96                // Create a result
97                let mut result = SampleResult {
98                    assignments,
99                    energy,
100                    occurrences: 1,
101                };
102
103                results.push(result);
104            }
105
106            Ok(results)
107        }
108
109        #[cfg(not(feature = "dwave"))]
110        {
111            Err(SamplerError::DWaveUnavailable(
112                "D-Wave support not enabled. Rebuild with '--features dwave'".to_string(),
113            ))
114        }
115    }
116
117    fn run_hobo(
118        &self,
119        hobo: &(
120            Array<f64, scirs2_core::ndarray::IxDyn>,
121            HashMap<String, usize>,
122        ),
123        shots: usize,
124    ) -> SamplerResult<Vec<SampleResult>> {
125        // For HOBO problems, we need to first convert to QUBO if possible
126        if hobo.0.ndim() <= 2 {
127            // If it's already 2D, just forward to run_qubo
128            let qubo = (
129                hobo.0.clone().into_dimensionality::<Ix2>().map_err(|e| {
130                    SamplerError::InvalidParameter(format!("Failed to convert to 2D array: {}", e))
131                })?,
132                hobo.1.clone(),
133            );
134            self.run_qubo(&qubo, shots)
135        } else {
136            // D-Wave doesn't directly support higher-order problems
137            // We could implement automatic quadratization here, but for now return an error
138            Err(SamplerError::InvalidParameter(
139                "D-Wave doesn't support HOBO problems directly. Use a quadratization technique first.".to_string()
140            ))
141        }
142    }
143}
quantrs2_tytan/sampler/hardware/dwave.rs

quantrs2_tytan/sampler/hardware/
dwave.rs
