open-standards/wai/wai-quantum/examples/sv_run.rs

//! Run a circuit (JSON lines, one gate per line: {"q":[a,b],"m":[re,im,…]}) on
//! the dense state vector and print the final state, or time it.
//!
//! ```text
//! cargo run --release --example sv_run --features quantum_sv -- CIRCUIT N WIDTH [--state | --time]
//! ```
use wai_quantum::gates::{complex, Gate};
use wai_quantum::quantum_sv::StateVector;

fn main() {
    let a: Vec<String> = std::env::args().collect();
    let text = std::fs::read_to_string(&a[1]).expect("read circuit");
    let n: u32 = a[2].parse().unwrap();
    let width: usize = a[3].parse().unwrap();
    let gates: Vec<Gate> = text
        .lines()
        .filter(|l| !l.trim().is_empty())
        .map(|l| {
            let v: serde_json::Value = serde_json::from_str(l).unwrap();
            let qubits = v["q"].as_array().unwrap().iter().map(|x| x.as_u64().unwrap() as u32).collect();
            let m: Vec<f64> = v["m"].as_array().unwrap().iter().map(|x| x.as_f64().unwrap()).collect();
            Gate { qubits, matrix: m.chunks(2).map(|c| complex(c[0], c[1])).collect() }
        })
        .collect();
    let mut sv = StateVector::zero(n).unwrap();
    let t0 = std::time::Instant::now();
    sv.run(&gates, width).unwrap();
    let dt = t0.elapsed().as_secs_f64();
    if a.iter().any(|x| x == "--state") {
        let amps: Vec<String> = (0..sv.re.len()).map(|x| format!("[{:e},{:e}]", sv.re[x], sv.im[x])).collect();
        println!("[{}]", amps.join(","));
    } else {
        println!("{n} qubits, {} gates, width {width}: {dt:.3} s, norm {:.15}", gates.len(), sv.norm2());
    }
}