From 357888e311b93ff4bf2deccadf89fa9a57219399 Mon Sep 17 00:00:00 2001
From: Matej Focko <mfocko@redhat.com>
Date: Sat, 10 Dec 2022 12:47:57 +0100
Subject: [PATCH] day(10): add initial solution

Signed-off-by: Matej Focko <mfocko@redhat.com>
---
 samples/day10.txt | 146 ++++++++++++++++++++++++++++++++++++++++++++
 src/bin/day10.rs  | 150 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 296 insertions(+)
 create mode 100644 samples/day10.txt
 create mode 100644 src/bin/day10.rs

diff --git a/samples/day10.txt b/samples/day10.txt
new file mode 100644
index 0000000..94cd0a8
--- /dev/null
+++ b/samples/day10.txt
@@ -0,0 +1,146 @@
+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
\ No newline at end of file
diff --git a/src/bin/day10.rs b/src/bin/day10.rs
new file mode 100644
index 0000000..63de3b3
--- /dev/null
+++ b/src/bin/day10.rs
@@ -0,0 +1,150 @@
+use std::str::FromStr;
+
+use aoc_2022::*;
+
+use color_eyre::{eyre::eyre, Report};
+use itertools::Itertools;
+use tracing::{debug, info};
+
+type Input = Vec<Instruction>;
+type Output = i32;
+
+#[derive(Debug)]
+enum Instruction {
+    Addx(i32),
+    Noop,
+}
+
+impl FromStr for Instruction {
+    type Err = Report;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let split_s = s.split_ascii_whitespace().collect_vec();
+
+        match split_s[0] {
+            "noop" => Ok(Instruction::Noop),
+            "addx" => {
+                let value: i32 = split_s[1].parse()?;
+                Ok(Instruction::Addx(value))
+            }
+            _ => Err(eyre!("Invalid instruction {}", split_s[0])),
+        }
+    }
+}
+
+struct State {
+    cycle: i32,
+    register: i32,
+}
+
+impl State {
+    fn new() -> Self {
+        Self {
+            cycle: 1,
+            register: 1,
+        }
+    }
+
+    fn execute(&self, i: &Instruction) -> (State, i32) {
+        let next = match i {
+            Instruction::Addx(value) => State {
+                cycle: self.cycle + 2,
+                register: self.register + value,
+            },
+            Instruction::Noop => State {
+                cycle: self.cycle + 1,
+                register: self.register,
+            },
+        };
+        // debug!("New state of CPU: cycle={}, register={}", next.cycle, next.register);
+
+        let strength = if let Some(cycle) =
+            (self.cycle..next.cycle).find(|&c| c >= 20 && (c + 20) % 40 == 0)
+        {
+            // debug!(
+            //     "Adding {} x {} = {} to sum",
+            //     cycle,
+            //     self.register,
+            //     cycle * self.register
+            // );
+
+            cycle * self.register
+        } else {
+            0
+        };
+
+        (next, strength)
+    }
+
+    fn execute_and_draw(&self, i: &Instruction, screen: &mut Vec<Vec<char>>) -> State {
+        let next = match i {
+            Instruction::Addx(value) => State {
+                cycle: self.cycle + 2,
+                register: self.register + value,
+            },
+            Instruction::Noop => State {
+                cycle: self.cycle + 1,
+                register: self.register,
+            },
+        };
+        // debug!("New state of CPU: cycle={}, register={}", next.cycle, next.register);
+
+        // debug!("Checking: {:?} {:?}", i, (self.cycle..next.cycle));
+        (self.cycle..next.cycle).for_each(|c| {
+            let idx = screen.len() - 1;
+            screen[idx].push(
+                if self.register - 1 <= (c - 1) % 40 && (c - 1) % 40 <= self.register + 1 {
+                    '█'
+                } else {
+                    ' '
+                },
+            );
+            // debug!("{} ; {} <= {} <= {}", screen[idx].last().unwrap(), self.register - 1, c % 40, self.register + 1);
+
+            if c % 40 == 0 {
+                screen.push(Vec::new());
+            }
+        });
+
+        next
+    }
+}
+
+struct Day10;
+impl Solution<Input, Output> for Day10 {
+    fn parse_input<P: AsRef<Path>>(pathname: P) -> Input {
+        file_to_structs(pathname)
+    }
+
+    fn part_1(input: &Input) -> Output {
+        input
+            .iter()
+            .fold((State::new(), 0), |(state, strength_sum), instruction| {
+                let (new_state, strength) = state.execute(instruction);
+
+                (new_state, strength_sum + strength)
+            })
+            .1
+    }
+
+    fn part_2(input: &Input) -> Output {
+        let mut screen: Vec<Vec<char>> = vec![vec![]];
+
+        input.iter().fold(State::new(), |state, instruction| {
+            state.execute_and_draw(instruction, &mut screen)
+        });
+
+        info!(
+            "Screen:\n{}",
+            screen.iter().map(|line| line.iter().join("")).join("\n")
+        );
+
+        0
+    }
+}
+
+fn main() -> Result<()> {
+    Day10::main()
+}
+
+test_sample!(day_10, Day10, 13140, 1);