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path: root/2018/src/day19.rs
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use std::io;
use std::io::BufRead;
use crate::device::*;

#[allow(dead_code)]
fn optimise(mut instrs: Vec<Instr>, ip_reg: usize) -> Vec<Instr> {
    for i in 0..instrs.len() {
        instrs[i].inline_reg(ip_reg, Oper::Num(i));
    }

    instrs
}

#[allow(dead_code)]
fn run_program(instrs: &[Instr], r0: usize, ip_reg: usize) -> usize {
    let mut m = Machine { regs: [r0, 0, 0, 0, 0, 0] };
    m.exec_program(&instrs, ip_reg);
    m.regs[0]
}

fn divisor_sum(n: i64) -> i64 {
    (1..n+1).filter(|&d| n % d == 0).sum()
}

fn main_alt() -> (String, String) {
    (divisor_sum(948).to_string(), divisor_sum(10551348).to_string())
}

pub fn main<T: BufRead>(_reader: T) -> io::Result<(String, String)> {
    Ok(main_alt())

    /* let (ip_reg, instrs) = parse_program(reader)?;

    // for instr in &instrs { println!("{}", instr); }

    let instrs = optimise(instrs, ip_reg);

    for instr in &instrs { println!("{}", instr); }

    // let part1 = run_program(&instrs, 0);
    let part2 = run_program(&instrs, 1, ip_reg);

    // Ok((part1.to_string(), part2.to_string()))
    Ok((String::new(), String::new())) */
}