diff options
Diffstat (limited to 'src/bin/day10.rs')
| -rw-r--r-- | src/bin/day10.rs | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/src/bin/day10.rs b/src/bin/day10.rs new file mode 100644 index 0000000..e8909c9 --- /dev/null +++ b/src/bin/day10.rs @@ -0,0 +1,248 @@ +static DAY: u8 = 10; + +fn main() { + let input = advent::read_lines(DAY); + println!("{DAY}a: {}", signal_strengths(&input)); + println!("{DAY}b: \n{}", display_output(&input)); +} + +enum Instruction { + Noop, + Addx { value: isize }, +} + +impl Instruction { + fn new(input: &str) -> Instruction { + if let Some((instr, val)) = input.split_once(' ') { + match instr { + "addx" => Instruction::Addx { value: val.parse().unwrap() }, + _ => unimplemented!(), + } + } else { + match input { + "noop" => Instruction::Noop, + _ => unimplemented!(), + } + } + } + + fn cycletime(&self) -> usize { + match *self { + Instruction::Noop => 1, + Instruction::Addx { value: _ } => 2, + } + } +} + +struct Cpu { + x: isize, +} + +fn run_program(input: &[String]) -> (isize, String) { + let mut instructions = input.iter() + .rev() + .map(|x| Instruction::new(x)) + .collect::<Vec<_>>(); + let mut cpu = Cpu { x: 1 }; + let mut cycle = 0; + let mut sigstr = 0; + let mut display = String::with_capacity(246); + + while let Some(instr) = instructions.pop() { + for _ in 0 .. instr.cycletime() { + cycle += 1; + if cycle % 40 == 20 { + sigstr += cycle * cpu.x; + } + if [cpu.x - 1, cpu.x, cpu.x + 1].contains(&((cycle - 1) % 40)) { + display.push('#'); + } else { + display.push('.'); + } + if cycle % 40 == 0 { + display.push('\n'); + } + } + match instr { + Instruction::Addx { value } => cpu.x += value, + Instruction::Noop => {}, + } + } + + (sigstr, display) +} + +fn signal_strengths(input: &[String]) -> isize { + run_program(input).0 +} + +fn display_output(input: &[String]) -> String { + run_program(input).1 +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn test_signalstrength() { + let input = [ + "addx 15", + "addx -11", + "addx 6", + "addx -3", + "addx 5", + "addx -1", + "addx -8", + "addx 13", + "addx 4", + "noop", + "addx -1", + "addx 5", + "addx -1", + "addx 5", + "addx -1", + "addx 5", + "addx -1", + "addx 5", + "addx -1", + "addx -35", + "addx 1", + "addx 24", + "addx -19", + "addx 1", + "addx 16", + "addx -11", + "noop", + "noop", + "addx 21", + "addx -15", + "noop", + "noop", + "addx -3", + "addx 9", + "addx 1", + "addx -3", + "addx 8", + "addx 1", + "addx 5", + "noop", + "noop", + "noop", + "noop", + "noop", + "addx -36", + "noop", + "addx 1", + "addx 7", + "noop", + "noop", + "noop", + "addx 2", + "addx 6", + "noop", + "noop", + "noop", + "noop", + "noop", + "addx 1", + "noop", + "noop", + "addx 7", + "addx 1", + "noop", + "addx -13", + "addx 13", + "addx 7", + "noop", + "addx 1", + "addx -33", + "noop", + "noop", + "noop", + "addx 2", + "noop", + "noop", + "noop", + "addx 8", + "noop", + "addx -1", + "addx 2", + "addx 1", + "noop", + "addx 17", + "addx -9", + "addx 1", + "addx 1", + "addx -3", + "addx 11", + "noop", + "noop", + "addx 1", + "noop", + "addx 1", + "noop", + "noop", + "addx -13", + "addx -19", + "addx 1", + "addx 3", + "addx 26", + "addx -30", + "addx 12", + "addx -1", + "addx 3", + "addx 1", + "noop", + "noop", + "noop", + "addx -9", + "addx 18", + "addx 1", + "addx 2", + "noop", + "noop", + "addx 9", + "noop", + "noop", + "noop", + "addx -1", + "addx 2", + "addx -37", + "addx 1", + "addx 3", + "noop", + "addx 15", + "addx -21", + "addx 22", + "addx -6", + "addx 1", + "noop", + "addx 2", + "addx 1", + "noop", + "addx -10", + "noop", + "noop", + "addx 20", + "addx 1", + "addx 2", + "addx 2", + "addx -6", + "addx -11", + "noop", + "noop", + "noop", + ].iter().map(|&x| String::from(x)).collect::<Vec<_>>(); + + assert_eq!(signal_strengths(&input), 13140); + + let expected = "##..##..##..##..##..##..##..##..##..##..\n\ + ###...###...###...###...###...###...###.\n\ + ####....####....####....####....####....\n\ + #####.....#####.....#####.....#####.....\n\ + ######......######......######......####\n\ + #######.......#######.......#######.....\n"; + assert_eq!(display_output(&input), expected); + } +} |