// main.rs

extern crate quantum2;
use quantum2::computer::QuantumComputer;
use quantum2::algorithms::deutsch;
use quantum2::gates;

fn main() {
    // Let's do something simple of a 3-qubit system.
    let mut c1 = QuantumComputer::new(3);
    c1.initialize(5);
    c1.apply(gates::identity(3));
    c1.collapse();
    assert_eq!(5, c1.value());

    // Now let's perform a coin flip using the Hadamard transform.
    let mut c2 = QuantumComputer::new(1);
    c2.initialize(0);
    c2.apply(gates::hadamard(1));
    c2.collapse();
    let result = if 1 == c2.value() { "heads" } else { "tails" };
    println!("coin flip: {}", result);

    // Finally let's determine whether f: {0, 1} -> {0, 1} is constant
    // or balanced using Deutsch's algorithm.
    // (see http://physics.stackexchange.com/q/3400)
    let mut c3 = QuantumComputer::new(2);
    c3.initialize(1);
    c3.apply(gates::hadamard(2));
    c3.apply(deutsch::deutsch_gate(f));
    c3.apply(gates::hadamard(2));
    c3.collapse();
    let result = if 1 == c3.value() { "constant" } else { "balanced" };
    println!("f is: {}", result);
}

fn f(x: i32) -> i32 {
    1 - x
}