Day 22 part 1

2021/input/2021/day21.txt

@@ -0,0 +1,2 @@
+Player 1 starting position: 4
+Player 2 starting position: 5

2021/src/day21.rs

@@ -0,0 +1,171 @@
+use advent::prelude::*;
+use aoc_runner_derive::aoc;
+
+#[derive(Copy, Clone, Debug)]
+struct Player {
+    tally: usize,
+    score: usize,
+}
+
+impl Player {
+    fn space(&self) -> usize {
+        (self.tally % 10) + 1
+    }
+}
+
+#[derive(Debug, Default)]
+struct Die {
+    roll_count: usize,
+}
+
+impl Die {
+    fn roll(&mut self) -> usize {
+        let val = (self.roll_count % 100) + 1;
+        self.roll_count += 1;
+        val
+    }
+}
+
+fn take_turn(p: &mut Player, die: &mut Die) -> bool {
+    p.tally += die.roll() + die.roll() + die.roll();
+    p.score += p.space();
+
+    if p.score >= 1000 {
+        return true;
+    }
+    false
+}
+
+#[aoc(day21, part1)]
+fn part1(input: &str) -> Result<usize> {
+    let mut p: Vec<_> = input
+        .lines()
+        .map(|l| l.split_once(": ").unwrap())
+        .map(|(_, space)| space.parse().expect("couldn't parse starting spaceition"))
+        .map(|space: usize| Player {
+            tally: space - 1,
+            score: 0,
+        })
+        .collect();
+    let mut die = Die::default();
+    loop {
+        if take_turn(&mut p[0], &mut die) {
+            return Ok(die.roll_count * p[1].score);
+        }
+        //println!( "Player 1 space {} for a total score of {}.", p[0].space(), p[0].score);
+
+        if take_turn(&mut p[1], &mut die) {
+            return Ok(die.roll_count * p[0].score);
+        }
+        //println!( "Player 2 space {} for a total score of {}.", p[1].space(), p[1].score);
+    }
+}
+
+fn play_part2(p1: Player, p2: Player) -> (usize, usize) {
+    fn play_part2_rec(
+        mut p1: Player,
+        mut p2: Player,
+        r1: usize,
+        r2: usize,
+        r3: usize,
+        r4: usize,
+        r5: usize,
+        r6: usize,
+    ) -> (usize, usize) {
+        //println!( "p1 {} {} p2 {} {} die {} {} {} {} {} {}", p1.score, p1.space(), p2.score, p2.space(), r1, r2, r3, r4, r5, r6,);
+        p1.tally += r1 + r2 + r3;
+        p1.score += p1.space();
+        if p1.score >= 21 {
+            return (1, 0);
+        }
+
+        p2.tally += r4 + r5 + r6;
+        p2.score += p2.space();
+        if p2.score >= 21 {
+            return (0, 1);
+        }
+
+        let mut p1_score = 0;
+        let mut p2_score = 0;
+
+        for i in [1, 2, 3] {
+            for j in [1, 2, 3] {
+                for k in [1, 2, 3] {
+                    for x in [1, 2, 3] {
+                        for y in [1, 2, 3] {
+                            for z in [1, 2, 3] {
+                                let (p1s, p2s) = play_part2_rec(p1, p2, i, j, k, x, y, z);
+                                p1_score += p1s;
+                                p2_score += p2s;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        (p1_score, p2_score)
+    }
+
+    let mut p1_score = 0;
+    let mut p2_score = 0;
+
+    for i in [1, 2, 3] {
+        for j in [1, 2, 3] {
+            for k in [1, 2, 3] {
+                for x in [1, 2, 3] {
+                    for y in [1, 2, 3] {
+                        for z in [1, 2, 3] {
+                            let (p1s, p2s) = play_part2_rec(p1, p2, i, j, k, x, y, z);
+                            p1_score += p1s;
+                            p2_score += p2s;
+                            println!("Running score {} vs {}", p1_score, p2_score);
+                        }
+                    }
+                }
+            }
+        }
+    }
+    (p1_score, p2_score)
+}
+
+//#[aoc(day21, part2)]
+fn part2(input: &str) -> Result<usize> {
+    let p: Vec<_> = input
+        .lines()
+        .map(|l| l.split_once(": ").unwrap())
+        .map(|(_, space)| space.parse().expect("couldn't parse starting spaceition"))
+        .map(|space: usize| Player {
+            tally: space - 1,
+            score: 0,
+        })
+        .collect();
+    let (p1_wins, p2_wins) = play_part2(p[0], p[1]);
+    Ok(if p1_wins > p2_wins { p1_wins } else { p2_wins })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part1() -> Result<()> {
+        let input = r#"
+Player 1 starting position: 4
+Player 2 starting position: 8
+"#
+        .trim();
+        assert_eq!(part1(input)?, 739785);
+        Ok(())
+    }
+
+    //#[test]
+    fn test_part2() -> Result<()> {
+        let input = r#"
+Player 1 starting position: 4
+Player 2 starting position: 8
+"#
+        .trim();
+        assert_eq!(part2(input)?, 444356092776315);
+        Ok(())
+    }
+}

2021/src/day22.rs

@@ -0,0 +1,144 @@
+use advent::prelude::*;
+use aoc_runner_derive::aoc;
+
+#[derive(Debug)]
+struct Instruction {
+    on: bool,
+    x_rng: RangeInclusive<i64>,
+    y_rng: RangeInclusive<i64>,
+    z_rng: RangeInclusive<i64>,
+}
+
+impl FromStr for Instruction {
+    type Err = Infallible;
+
+    fn from_str(input: &str) -> std::result::Result<Instruction, Infallible> {
+        // on x=11..13,y=11..13,z=11..13
+        // off x=9..11,y=9..11,z=9..11
+        let (verb, rest) = input.split_once(' ').unwrap();
+        let on = match verb {
+            "on" => true,
+            "off" => false,
+            _ => unreachable!("unexpected instruction type"),
+        };
+
+        let parts: Vec<_> = rest.split(',').collect();
+        let parse_rng = |s: &str| -> RangeInclusive<i64> {
+            s.split_once('=')
+                .unwrap()
+                .1
+                .split_once("..")
+                .map(|(lo, hi)| (lo.parse().unwrap(), hi.parse().unwrap()))
+                .map(|(lo, hi)| lo..=hi)
+                .unwrap()
+        };
+        let x_rng = parse_rng(parts[0]);
+        let y_rng = parse_rng(parts[1]);
+        let z_rng = parse_rng(parts[2]);
+        Ok(Instruction {
+            on,
+            x_rng,
+            y_rng,
+            z_rng,
+        })
+    }
+}
+
+fn part1_apply(insts: Vec<Instruction>) -> usize {
+    let mut grid = HashSet::new();
+    for inst in &insts {
+        dbg!(&inst);
+        for x in inst.x_rng.clone() {
+            for y in inst.y_rng.clone() {
+                for z in inst.z_rng.clone() {
+                    if inst.on {
+                        grid.insert((x, y, z));
+                    } else {
+                        grid.remove(&(x, y, z));
+                    }
+                }
+            }
+        }
+    }
+    grid.len()
+}
+
+fn inbounds(r: &RangeInclusive<i64>) -> bool {
+    // lazy but good enough for part1
+    r.start().abs() <= 50
+}
+
+#[aoc(day22, part1)]
+fn part1(input: &str) -> Result<usize> {
+    let insts: Vec<Instruction> = input
+        .lines()
+        .map(|l| l.parse().expect("failed to parse instruction"))
+        .filter(|i: &Instruction| inbounds(&i.x_rng) && inbounds(&i.y_rng) && inbounds(&i.z_rng))
+        .collect();
+    dbg!(&insts);
+    Ok(part1_apply(insts))
+}
+
+/*
+#[aoc(day22, part2)]
+fn part2(input: &str) -> Result<usize> {
+todo!("part2");
+Ok(0)
+}
+*/
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part1() -> Result<()> {
+        let input = r#"
+        on x=10..12,y=10..12,z=10..12
+on x=11..13,y=11..13,z=11..13
+off x=9..11,y=9..11,z=9..11
+on x=10..10,y=10..10,z=10..10
+"#
+        .trim();
+        assert_eq!(part1(input)?, 39);
+
+        let input = r#"
+        on x=-20..26,y=-36..17,z=-47..7
+on x=-20..33,y=-21..23,z=-26..28
+on x=-22..28,y=-29..23,z=-38..16
+on x=-46..7,y=-6..46,z=-50..-1
+on x=-49..1,y=-3..46,z=-24..28
+on x=2..47,y=-22..22,z=-23..27
+on x=-27..23,y=-28..26,z=-21..29
+on x=-39..5,y=-6..47,z=-3..44
+on x=-30..21,y=-8..43,z=-13..34
+on x=-22..26,y=-27..20,z=-29..19
+off x=-48..-32,y=26..41,z=-47..-37
+on x=-12..35,y=6..50,z=-50..-2
+off x=-48..-32,y=-32..-16,z=-15..-5
+on x=-18..26,y=-33..15,z=-7..46
+off x=-40..-22,y=-38..-28,z=23..41
+on x=-16..35,y=-41..10,z=-47..6
+off x=-32..-23,y=11..30,z=-14..3
+on x=-49..-5,y=-3..45,z=-29..18
+off x=18..30,y=-20..-8,z=-3..13
+on x=-41..9,y=-7..43,z=-33..15
+on x=-54112..-39298,y=-85059..-49293,z=-27449..7877
+on x=967..23432,y=45373..81175,z=27513..53682
+"#
+        .trim();
+        assert_eq!(part1(input)?, 590784);
+        Ok(())
+    }
+
+    /*
+    #[test]
+    fn test_part2()->Result<()> {
+    let input = r#"
+    "#
+    .trim();
+    assert_eq!(part2(input)?, usize::MAX);
+    Ok(())
+    }
+    */
+}

2021/src/lib.rs

@@ -10,6 +10,8 @@ pub mod day17;
 //pub mod day18;
 pub mod day2;
 pub mod day20;
+pub mod day21;
+pub mod day22;
 pub mod day3;
 pub mod day4;
 pub mod day5;

2021/src/template.rs

@@ -1,5 +1,5 @@
 use advent::prelude::*;
-use aoc_runner_derive::{aoc, aoc_generator};
+use aoc_runner_derive::aoc;
 
 #[aoc(dayX, part1)]
 fn part1(input: &str) -> Result<usize> {

src/lib.rs

@@ -5,7 +5,7 @@ pub mod prelude {
         fmt::{Debug, Display, Error, Formatter},
         io::Read,
         num::ParseIntError,
-        ops::{Index, IndexMut},
+        ops::{Index, IndexMut, RangeInclusive},
         str::FromStr,
     };