feat: day 17 + fmt

data/examples/17.txt

@@ -0,0 +1,5 @@
+Register A: 729
+Register B: 0
+Register C: 0
+
+Program: 0,1,5,4,3,0

src/bin/16.rs

@@ -1,7 +1,7 @@
 advent_of_code::solution!(16);
 
-use std::collections::HashMap;
 use std::collections::vec_deque::VecDeque;
+use std::collections::HashMap;
 
 #[derive(Debug, Clone, Hash, PartialEq, Eq)]
 struct Pos {
@@ -13,13 +13,37 @@ impl Pos {
     fn neighbors(&self) -> Vec<Step> {
         let mut res: Vec<Step> = Vec::new();
         if self.x > 0 {
-            res.push(Step { pos: Pos { x: self.x - 1, y: self.y }, dir: Dir::Left });
+            res.push(Step {
+                pos: Pos {
+                    x: self.x - 1,
+                    y: self.y,
+                },
+                dir: Dir::Left,
+            });
         }
         if self.y > 0 {
-            res.push(Step { pos: Pos { x: self.x, y: self.y - 1 }, dir: Dir::Up });
+            res.push(Step {
+                pos: Pos {
+                    x: self.x,
+                    y: self.y - 1,
+                },
+                dir: Dir::Up,
+            });
         }
-        res.push(Step { pos: Pos { x: self.x + 1, y: self.y }, dir: Dir::Right });
+        res.push(Step {
-        res.push(Step { pos: Pos { x: self.x, y: self.y + 1 }, dir: Dir::Down });
+            pos: Pos {
+                x: self.x + 1,
+                y: self.y,
+            },
+            dir: Dir::Right,
+        });
+        res.push(Step {
+            pos: Pos {
+                x: self.x,
+                y: self.y + 1,
+            },
+            dir: Dir::Down,
+        });
         res
     }
 }
@@ -48,13 +72,16 @@ struct Step {
 
 #[derive(Debug, Clone)]
 struct Path {
-    steps: VecDeque<Step>
+    steps: VecDeque<Step>,
 }
 
 impl Path {
     fn init(pos: Pos) -> Self {
         Self {
-            steps: VecDeque::from(vec![Step {pos, dir: Dir::Right}]),
+            steps: VecDeque::from(vec![Step {
+                pos,
+                dir: Dir::Right,
+            }]),
         }
     }
 
@@ -90,19 +117,22 @@ impl TryFrom<&str> for State {
     type Error = ();
     fn try_from(input: &str) -> Result<State, Self::Error> {
         let input = input.lines().collect::<Vec<_>>();
-        let size = Pos { x: input[0].len(), y: input.len() };
+        let size = Pos {
-        let input: Vec<(Pos, char)> = input.iter()
+            x: input[0].len(),
+            y: input.len(),
+        };
+        let input: Vec<(Pos, char)> = input
+            .iter()
             .enumerate()
-            .flat_map(|(y, l)|
+            .flat_map(|(y, l)| {
-                l
+                l.chars().enumerate().filter_map(move |(x, c)| {
-                    .chars()
-                    .enumerate()
-                    .filter_map(move |(x, c)|
                     if c == '#' {
                         None
                     } else {
                         Some((Pos { x, y }, c))
-                        }))
+                    }
+                })
+            })
             .collect();
         let start = input.iter().find(|(_, c)| *c == 'S').ok_or(())?.0.clone();
         let end = input.iter().find(|(_, c)| *c == 'E').ok_or(())?.0.clone();
@@ -128,8 +158,11 @@ impl State {
             all_paths.push(path);
             return;
         }
-        for next in cur.neighbors().iter()
+        for next in cur
-            .filter(|p| self.map.contains_key(&p.pos) && !path.have_visited(&p.pos)) {
+            .neighbors()
+            .iter()
+            .filter(|p| self.map.contains_key(&p.pos) && !path.have_visited(&p.pos))
+        {
             let mut new_path = path.clone();
             new_path.push(next.clone());
             self.compute_all_paths(new_path, all_paths);

src/bin/17.rs

@@ -0,0 +1,192 @@
+advent_of_code::solution!(17);
+
+use std::iter::successors;
+
+#[derive(Debug, Clone)]
+struct State {
+    registers: [i32; 3],
+    memory: Vec<i32>,
+    ptr: usize,
+    output: Vec<i32>,
+}
+
+impl State {
+    fn dv(&self, reg: usize, combo: i32) -> Option<Self> {
+        println!(
+            "DIV reg 0 {} / 2^{} => reg {}",
+            self.registers[0], combo, reg
+        );
+        let two: i32 = 2;
+        let res = self.registers[0].checked_div(two.pow(combo as u32))?;
+        let mut new_registers = self.registers.clone();
+        new_registers[reg] = res;
+        Some(Self {
+            registers: new_registers,
+            ptr: self.ptr + 2,
+            ..self.clone()
+        })
+    }
+
+    fn bxl(&self, combo: i32) -> Option<Self> {
+        println!("BXL reg 1 ^ {} => reg 1", combo);
+        let res = self.registers[1] ^ combo;
+        let mut new_registers = self.registers.clone();
+        new_registers[1] = res;
+        Some(Self {
+            registers: new_registers,
+            ptr: self.ptr + 2,
+            ..self.clone()
+        })
+    }
+
+    fn bst(&self, combo: i32) -> Option<Self> {
+        println!("BST {} % 8 => reg 1", combo);
+        let mut new_registers = self.registers.clone();
+        new_registers[1] = combo % 8;
+        Some(Self {
+            registers: new_registers,
+            ptr: self.ptr + 2,
+            ..self.clone()
+        })
+    }
+
+    fn jnz(&self, combo: i32) -> Option<Self> {
+        if self.registers[0] == 0 {
+            println!("JNZ reg 0 == 0 => NO-OP");
+            Some(Self {
+                ptr: self.ptr + 2,
+                ..self.clone()
+            })
+        } else {
+            println!("JNZ reg 0 != 0 => JMP {}", combo);
+            Some(Self {
+                ptr: combo as usize,
+                ..self.clone()
+            })
+        }
+    }
+
+    fn bxc(&self) -> Option<Self> {
+        println!("BXC reg 1 ^ reg 2 => reg 1");
+        let mut new_registers = self.registers.clone();
+        new_registers[1] = self.registers[1] ^ self.registers[2];
+        Some(Self {
+            registers: new_registers,
+            ptr: self.ptr + 2,
+            ..self.clone()
+        })
+    }
+
+    fn out(&self, combo: i32) -> Option<Self> {
+        println!("OUT {} % 8 => out", combo);
+        let mut new_out = self.output.clone();
+        new_out.push(combo % 8);
+        Some(Self {
+            output: new_out,
+            ptr: self.ptr + 2,
+            ..self.clone()
+        })
+    }
+
+    fn run(&self) -> Self {
+        successors(Some(self.clone()), |st| st.step())
+            .last()
+            .unwrap()
+    }
+
+    fn step(&self) -> Option<Self> {
+        println!("Current state\n{:?}", self);
+        if self.ptr >= self.memory.len() {
+            return None;
+        }
+        let opcode = self.memory.get(self.ptr).unwrap();
+        let combo = *self.memory.get(self.ptr + 1).unwrap();
+        if combo < 0 || combo > 6 {
+            return None;
+        }
+        let combo_value = match combo {
+            0..=3 => combo,
+            4 => self.registers[0],
+            5 => self.registers[1],
+            6 => self.registers[2],
+            _ => panic!(),
+        };
+        match opcode {
+            0 => self.dv(0, combo_value),
+            1 => self.bxl(combo_value),
+            2 => self.bst(combo_value),
+            3 => self.jnz(combo_value),
+            4 => self.bxc(),
+            5 => self.out(combo_value),
+            6 => self.dv(1, combo_value),
+            7 => self.dv(2, combo_value),
+            _ => None,
+        }
+    }
+    fn get_output(&self) -> String {
+        let vec: Vec<String> = self.output.iter().map(|n| n.to_string()).collect();
+        vec.join(",")
+    }
+}
+
+impl TryFrom<&str> for State {
+    type Error = ();
+    fn try_from(input: &str) -> Result<Self, Self::Error> {
+        let mut input = input
+            .lines()
+            .filter_map(|l| {
+                if l.is_empty() {
+                    None
+                } else {
+                    Some(
+                        l.split(": ")
+                            .skip(1)
+                            .flat_map(|s| {
+                                s.split(",")
+                                    .map(|n| n.parse::<i32>().unwrap())
+                                    .collect::<Vec<_>>()
+                            })
+                            .collect::<Vec<_>>(),
+                    )
+                }
+            })
+            .flatten()
+            .collect::<Vec<_>>();
+        if input.len() < 4 {
+            Err(())
+        } else {
+            let registers: [i32; 3] = [input.remove(0), input.remove(0), input.remove(0)];
+            Ok(State {
+                registers,
+                memory: input,
+                ptr: 0,
+                output: Vec::new(),
+            })
+        }
+    }
+}
+
+pub fn part_one(input: &str) -> Option<String> {
+    State::try_from(input).ok().map(|s| s.run().get_output())
+}
+
+pub fn part_two(input: &str) -> Option<u32> {
+    None
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let result = part_one(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some("4,6,3,5,6,3,5,2,1,0".into()));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, None);
+    }
+}