advent-of-code/aoc2019/src/day02.rs

100 lines
2.6 KiB
Rust

use std::fmt::Write;
use aoc::err;
use aoc::Result;
use crate::intcode::{parse_memory, Intcode};
const INPUT: &str = include_str!("../input/day02.txt");
const PART2_EXPECTED: i64 = 19_690_720;
pub fn run() -> Result<String> {
let mut res = String::with_capacity(128);
let memory = parse_memory(INPUT)?;
writeln!(res, "part 1: {}", part1(memory.clone())?)?;
writeln!(res, "part 2: {}", part2(&memory, PART2_EXPECTED)?)?;
Ok(res)
}
fn part1(mut input: Vec<i64>) -> Result<i64> {
input[1] = 12;
input[2] = 2;
let mut intcode = Intcode::with_memory(input);
intcode.run()?;
intcode
.get_day02_output()
.ok_or_else(|| err!("intcode memory was empty!"))
}
fn part2(input: &[i64], res: i64) -> Result<i64> {
for (noun, verb) in (0..=99).flat_map(|noun| (0..=99).map(move |verb| (noun, verb))) {
let mut test_input = input.to_vec();
test_input[1] = noun;
test_input[2] = verb;
let mut intcode = Intcode::with_memory(test_input);
intcode.run()?;
match intcode.get_day02_output() {
Some(val) => {
if val == res {
return Ok(noun * 100 + verb);
}
}
None => return Err(err!("intcode memory was empty!")),
}
}
Err(err!(
"couldn't find noun/verb combination that produces {}",
res
))
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn part1_provided() {
let mut intcode = Intcode::new("1,9,10,3,2,3,11,0,99,30,40,50").unwrap();
intcode.run().unwrap();
assert_eq!(
&intcode.memory,
&[3500, 9, 10, 70, 2, 3, 11, 0, 99, 30, 40, 50]
);
let mut intcode = Intcode::new("1,0,0,0,99").unwrap();
intcode.run().unwrap();
assert_eq!(&intcode.memory, &[2, 0, 0, 0, 99]);
let mut intcode = Intcode::new("2,3,0,3,99").unwrap();
intcode.run().unwrap();
assert_eq!(&intcode.memory, &[2, 3, 0, 6, 99]);
let mut intcode = Intcode::new("2,4,4,5,99,0").unwrap();
intcode.run().unwrap();
assert_eq!(&intcode.memory, &[2, 4, 4, 5, 99, 9801]);
let mut intcode = Intcode::new("1,1,1,4,99,5,6,0,99").unwrap();
intcode.run().unwrap();
assert_eq!(&intcode.memory, &[30, 1, 1, 4, 2, 5, 6, 0, 99]);
}
#[test]
fn part1_real() {
let memory = parse_memory(INPUT).unwrap();
assert_eq!(part1(memory).unwrap(), 6568671);
}
#[test]
fn part2_real() {
let memory = parse_memory(INPUT).unwrap();
assert_eq!(part2(&memory, PART2_EXPECTED).unwrap(), 3951);
}
}