advent_of_code/year2019/
day02.rs

1use super::int_code::Program;
2use super::int_code::Word;
3use crate::input::Input;
4
5pub fn solve(input: &Input) -> Result<Word, String> {
6    const DESIRED_OUTPUT: Word = 19_690_720;
7
8    let initial_program = Program::parse(input.text)?;
9
10    for noun in input.part_values(12..=12, 0..=99) {
11        for verb in input.part_values(2..=2, 0..=99) {
12            let mut program = initial_program.clone();
13            program.write_memory(1, noun);
14            program.write_memory(2, verb);
15            program.run_until_halt_or_input(10_000)?;
16            let memory_value = program.read_memory(0);
17            if input.is_part_one() {
18                return Ok(memory_value);
19            } else if memory_value == DESIRED_OUTPUT {
20                return Ok(100 * noun + verb);
21            }
22        }
23    }
24
25    Err(format!("Desired output {DESIRED_OUTPUT} is never produced"))
26}
27
28#[test]
29pub fn tests() {
30    use crate::input::{test_part_one, test_part_one_error, test_part_two};
31
32    let solution = include_str!("day02_input.txt");
33    test_part_one!(solution => 4_570_637);
34    test_part_two!(solution => 5485);
35
36    test_part_one_error!( "hi" => "Unable to parse program word (invalid digit found in string)");
37}
advent_of_code/year2019/day02.rs

advent_of_code/year2019/
day02.rs
