Day 8.1, 9 and 10, plus formatting and optimization

src/day02.rs

@@ -14,10 +14,10 @@ pub struct Instruction {
 }
 
 #[derive(Debug, Copy, Clone, Default)]
-pub struct Submarine{
+pub struct Submarine {
     depth: i64,
     pos: i64,
-    aim: i64
+    aim: i64,
 }
 
 impl Submarine {
@@ -45,7 +45,7 @@ impl Submarine {
         match d {
             Direction::Forward => {
                 self.pos += a;
-                self.depth += self.aim*a;
+                self.depth += self.aim * a;
             }
             Direction::Down => {
                 self.aim += a;

src/day03.rs

@@ -1,7 +1,5 @@
 use aoc_runner_derive::{aoc, aoc_generator};
-
 type Data = Vec<u16>;
-
 fn make_histogram(input: &[u16]) -> Vec<(usize, i64)> {
     let counts: &mut [Option<i64>] = &mut [None; 64];
     input.iter().for_each(|val| {
@@ -21,7 +19,6 @@ fn make_histogram(input: &[u16]) -> Vec<(usize, i64)> {
         .filter_map(|(a, b)| b.map(|b| (a, b)))
         .collect::<Vec<_>>()
 }
-
 #[aoc_generator(day03)]
 pub fn input_generator(input: &str) -> Vec<u16> {
     input
@@ -29,15 +26,12 @@ pub fn input_generator(input: &str) -> Vec<u16> {
         .map(|l| u16::from_str_radix(l, 2).unwrap())
         .collect()
 }
-
-
 #[derive(Debug)]
 enum Mode {
     MostCommon,
     LeastCommon,
 }
-
+fn tree_filter(data: &[u16], mut pos: usize, mode: Mode) -> u16 {
-fn tree_filter(data: &[u16], pos: usize, mode: Mode) -> u16 {
     let (zero, one) = data
         .iter()
         .partition::<Vec<u16>, _>(|&v| ((v >> pos) & 1) == 0);
@@ -47,24 +41,22 @@ fn tree_filter(data: &[u16], pos: usize, mode: Mode) -> u16 {
     if data.len() == 1 {
         return data[0];
     }
+    pos=pos.wrapping_sub(1);
     if zero.len() == one.len() {
         match mode {
-            Mode::MostCommon => tree_filter(&one, pos - 1, mode),
+            Mode::MostCommon => tree_filter(&one, pos, mode),
-            Mode::LeastCommon => tree_filter(&zero, pos - 1, mode),
+            Mode::LeastCommon => tree_filter(&zero, pos, mode),
         }
     } else {
         let mut srt = vec![zero, one];
         srt.sort_by_key(|v| v.len());
         match mode {
-            Mode::MostCommon => tree_filter(&srt[1], pos - 1, mode),
+            Mode::MostCommon => tree_filter(&srt[1], pos, mode),
-            Mode::LeastCommon => tree_filter(&srt[0], pos - 1, mode),
+            Mode::LeastCommon => tree_filter(&srt[0], pos, mode),
         }
     }
 }
-
-
 const ASCII_ZERO: u8 = 0x30;
-
 #[aoc(day03, part1)] // 1997414
 pub fn solve_part1(input: &Data) -> usize {
     let counts = make_histogram(input);
@@ -81,8 +73,7 @@ pub fn solve_part1(input: &Data) -> usize {
     let epsilon = usize::from_str_radix(&epsilon, 2).unwrap();
     gamma * epsilon
 }
-
+#[aoc(day03, part2)] // 1032597
-#[aoc(day03, part2)]
 pub fn solve_part2(input: &[u16]) -> usize {
     // let input: Vec<bool> = input.iter().for_each(|v| v[0]).collect();
     let a = tree_filter(input, 11, Mode::MostCommon) as usize;

src/day04.rs

@@ -1,9 +1,9 @@
 use aoc_runner_derive::{aoc, aoc_generator};
 
-#[derive(Debug,Clone)]
+#[derive(Debug, Clone)]
 pub struct Data {
     pub numbers: Vec<u8>,
-    pub boards: Vec<[[(u8,bool); 5]; 5]>,
+    pub boards: Vec<[[(u8, bool); 5]; 5]>,
 }
 
 #[aoc_generator(day04)]
@@ -18,7 +18,7 @@ pub fn input_generator(input: &str) -> Data {
         .collect::<Result<Vec<u8>, _>>()
         .unwrap();
     let mut row = 0;
-    let mut board = [[(0u8,false); 5]; 5];
+    let mut board = [[(0u8, false); 5]; 5];
     for line in lines {
         if line.is_empty() {
             continue;
@@ -29,12 +29,12 @@ pub fn input_generator(input: &str) -> Data {
             .collect::<Result<Vec<u8>, _>>()
             .unwrap();
         line.iter().enumerate().for_each(|(i, v)| {
-            board[row][i] = (*v,false);
+            board[row][i] = (*v, false);
         });
         row = (row + 1) % 5;
         if row == 0 {
             boards.push(board);
-            board = [[(0u8,false); 5]; 5];
+            board = [[(0u8, false); 5]; 5];
         }
     }
     Data { numbers, boards }
@@ -42,22 +42,48 @@ pub fn input_generator(input: &str) -> Data {
 
 #[aoc(day04, part1)]
 pub fn solve_part1(input: &Data) -> usize {
-    let Data {numbers,mut boards} =input.clone();
+    let Data {
+        numbers,
+        mut boards,
+    } = input.clone();
     for number in numbers.iter() {
         for board in &mut boards {
             for row in board.iter_mut() {
-                for (n,b) in row {
+                for (n, b) in row {
-                    if n==number {
+                    if n == number {
-                        *b=true;
+                        *b = true;
                     }
                 }
             }
-            let win=(0..5).map(|v| {
+            let win = (0..5)
-                [board[v][0],board[v][1],board[v][2],board[v][3],board[v][4]].iter().all(|v| v.1)|
+                .map(|v| {
-                [board[0][v],board[1][v],board[2][v],board[3][v],board[4][v]].iter().all(|v| v.1)
+                    [
-            }).any(|v| v);
+                        board[v][0],
+                        board[v][1],
+                        board[v][2],
+                        board[v][3],
+                        board[v][4],
+                    ]
+                    .iter()
+                    .all(|v| v.1)
+                        | [
+                            board[0][v],
+                            board[1][v],
+                            board[2][v],
+                            board[3][v],
+                            board[4][v],
+                        ]
+                        .iter()
+                        .all(|v| v.1)
+                })
+                .any(|v| v);
             if win {
-                return board.iter().flatten().filter_map(|(v,b)| (!*b).then(|| *v as usize)).sum::<usize>()*(*number as usize)
+                return board
+                    .iter()
+                    .flatten()
+                    .filter_map(|(v, b)| (!*b).then(|| *v as usize))
+                    .sum::<usize>()
+                    * (*number as usize);
             }
         }
     }
@@ -66,25 +92,54 @@ pub fn solve_part1(input: &Data) -> usize {
 
 #[aoc(day04, part2)]
 pub fn solve_part2(input: &Data) -> usize {
-    let mut ret=None;
+    let mut ret = None;
-    let Data {numbers,mut boards} =input.clone();
+    let Data {
-    let mut board_wins: Vec<bool> = vec![false;boards.len()];
+        numbers,
+        mut boards,
+    } = input.clone();
+    let mut board_wins: Vec<bool> = vec![false; boards.len()];
     for number in numbers.iter() {
-        for (board_n,board) in boards.iter_mut().enumerate() {
+        for (board_n, board) in boards.iter_mut().enumerate() {
             for row in board.iter_mut() {
-                for (n,b) in row {
+                for (n, b) in row {
-                    if n==number {
+                    if n == number {
-                        *b=true;
+                        *b = true;
                     }
                 }
             }
-            let win=(0..5).map(|v| {
+            let win = (0..5)
-                [board[v][0],board[v][1],board[v][2],board[v][3],board[v][4]].iter().all(|v| v.1)|
+                .map(|v| {
-                [board[0][v],board[1][v],board[2][v],board[3][v],board[4][v]].iter().all(|v| v.1)
+                    [
-            }).any(|v| v);
+                        board[v][0],
+                        board[v][1],
+                        board[v][2],
+                        board[v][3],
+                        board[v][4],
+                    ]
+                    .iter()
+                    .all(|v| v.1)
+                        | [
+                            board[0][v],
+                            board[1][v],
+                            board[2][v],
+                            board[3][v],
+                            board[4][v],
+                        ]
+                        .iter()
+                        .all(|v| v.1)
+                })
+                .any(|v| v);
             if win && !board_wins[board_n] {
-                ret=Some(board.iter().flatten().filter(|(_,b)| !*b).map(|(v,_)| *v as usize).sum::<usize>()*(*number as usize));
+                ret = Some(
-                board_wins[board_n]=true;
+                    board
+                        .iter()
+                        .flatten()
+                        .filter(|(_, b)| !*b)
+                        .map(|(v, _)| *v as usize)
+                        .sum::<usize>()
+                        * (*number as usize),
+                );
+                board_wins[board_n] = true;
             }
         }
     }

src/day05.rs

@@ -8,7 +8,7 @@ pub struct Line {
 
 impl Line {
     fn iter(&self) -> LineIterator {
-        let ret= LineIterator {
+        let ret = LineIterator {
             line: self,
             px: self.x.0,
             py: self.y.0,
@@ -23,7 +23,7 @@ impl Line {
                 std::cmp::Ordering::Greater => -1,
             },
         };
-        assert!(ret.sx!=0||ret.sy!=0);
+        assert!(ret.sx != 0 || ret.sy != 0);
         ret
     }
 }
@@ -40,21 +40,21 @@ impl<'a> Iterator for LineIterator<'a> {
     type Item = (i64, i64);
 
     fn next(&mut self) -> Option<Self::Item> {
-        let ret = (self.px,self.py);
+        let ret = (self.px, self.py);
-        if self.sx>0 && self.px>self.line.x.1 {
+        if self.sx > 0 && self.px > self.line.x.1 {
             return None;
         }
-        if self.sx<0 && self.px<self.line.x.1 {
+        if self.sx < 0 && self.px < self.line.x.1 {
             return None;
         }
-        if self.sy>0 && self.py>self.line.y.1 {
+        if self.sy > 0 && self.py > self.line.y.1 {
             return None;
         }
-        if self.sy<0 && self.py<self.line.y.1 {
+        if self.sy < 0 && self.py < self.line.y.1 {
             return None;
         }
-        self.px+=self.sx;
+        self.px += self.sx;
-        self.py+=self.sy;
+        self.py += self.sy;
         Some(ret)
     }
 }
@@ -66,7 +66,7 @@ pub fn input_generator(input: &str) -> Data {
     input
         .lines()
         .map(|line| {
-            let  parts= line.split(" -> ").collect::<Vec<_>>();
+            let parts = line.split(" -> ").collect::<Vec<_>>();
             let start = parts[0]
                 .split(',')
                 .map(|v| v.parse().unwrap())
@@ -86,9 +86,13 @@ pub fn input_generator(input: &str) -> Data {
 #[aoc(day05, part1)]
 pub fn solve_part1(input: &Data) -> usize {
     let mut grid = vec![vec![0u8; 1000]; 1000];
-    for (x,y) in input.iter().filter(|l| l.x.0==l.x.1||l.y.0==l.y.1).flat_map(|v| v.iter()) {
+    for (x, y) in input
-        let x: usize=x.try_into().unwrap();
+        .iter()
-        let y: usize=y.try_into().unwrap();
+        .filter(|l| l.x.0 == l.x.1 || l.y.0 == l.y.1)
+        .flat_map(|v| v.iter())
+    {
+        let x: usize = x.try_into().unwrap();
+        let y: usize = y.try_into().unwrap();
         grid[x][y] += 1;
     }
     return grid.iter().flatten().filter(|&v| *v > 1).count();
@@ -97,9 +101,9 @@ pub fn solve_part1(input: &Data) -> usize {
 #[aoc(day05, part2)]
 pub fn solve_part2(input: &Data) -> usize {
     let mut grid = vec![vec![0u8; 1000]; 1000];
-    for (x,y) in input.iter().flat_map(|v| v.iter()) {
+    for (x, y) in input.iter().flat_map(|v| v.iter()) {
-        let x: usize=x.try_into().unwrap();
+        let x: usize = x.try_into().unwrap();
-        let y: usize=y.try_into().unwrap();
+        let y: usize = y.try_into().unwrap();
         grid[x][y] += 1;
     }
     return grid.iter().flatten().filter(|&v| *v > 1).count();

src/day06.rs

@@ -1,33 +1,31 @@
 use aoc_runner_derive::{aoc, aoc_generator};
 
-type Data = [usize;9];
+type Data = [usize; 9];
 
 #[aoc_generator(day06)]
-pub fn input_generator(input: &str) -> [usize;9] {
+pub fn input_generator(input: &str) -> [usize; 9] {
-    let mut state: [usize;9] = [0;9];
+    let mut state: [usize; 9] = [0; 9];
     let input = input.trim().split(',').map(|v| v.parse::<usize>().unwrap());
     for v in input {
-        state[v]+=1;
+        state[v] += 1;
     }
     state
 }
 
-
+fn simulate(input: &Data, n: usize) -> usize {
-fn simulate(input: &Data,n: usize) -> usize {
+    let mut state = *input;
-    let mut state=*input;
     for i in 0..n {
-        state[(7+i)%9]+=state[i%9];
+        state[(7 + i) % 9] += state[i % 9];
     }
     state.iter().sum()
-
 }
 
 #[aoc(day06, part1)] // 353274
 pub fn solve_part1(input: &Data) -> usize {
-    simulate(input,80)
+    simulate(input, 80)
 }
 
 #[aoc(day06, part2)] // 1609314870967
 pub fn solve_part2(input: &Data) -> usize {
-    simulate(input,256)
+    simulate(input, 256)
 }

src/day07.rs

@@ -13,21 +13,26 @@ pub fn input_generator(input: &str) -> Data {
 pub fn solve_part1(input: &Data) -> i64 {
     let start = *input.first().unwrap();
     let end = *input.last().unwrap();
-    (start..=end).map(|n| {
+    (start..=end)
-        input.iter().map(|v| {
+        .map(|n| input.iter().map(|v| (v - n).abs()).sum())
-            (v-n).abs()
+        .min()
-        }).sum()
+        .unwrap()
-    }).min().unwrap()
 }
 
 #[aoc(day07, part2)] // 94813675
 pub fn solve_part2(input: &Data) -> i64 {
     let start = *input.first().unwrap();
     let end = *input.last().unwrap();
-    (start..=end).map(|n| {
+    (start..=end)
-        input.iter().map(|v| {
+        .map(|n| {
-            let diff=(v-n).abs();
+            input
-            (diff*(diff+1))>>1 // Gauss
+                .iter()
-        }).sum()
+                .map(|v| {
-    }).min().unwrap()
+                    let diff = (v - n).abs();
+                    (diff * (diff + 1)) >> 1 // Gauss
+                })
+                .sum()
+        })
+        .min()
+        .unwrap()
 }

src/day08.rs

@@ -0,0 +1,93 @@
+use std::collections::{BTreeSet, HashMap, HashSet};
+
+use aoc_runner_derive::{aoc, aoc_generator};
+use itertools::Itertools;
+
+type Data = HashMap<Vec<String>, Vec<String>>;
+
+#[aoc_generator(day08)]
+pub fn input_generator(input: &str) -> Data {
+    // let input =
+    //     "acedgfb cdfbe gcdfa fbcad dab cefabd cdfgeb eafb cagedb ab | cdfeb fcadb cdfeb cdbaf";
+    let mut ret = HashMap::new();
+    for line in input.lines() {
+        let mut line = line.split(" | ").map(|v| {
+            v.split(' ')
+                .map(|v| v.chars().sorted().collect::<String>())
+                .collect::<Vec<_>>()
+        });
+        ret.insert(line.next().unwrap(), line.next().unwrap());
+    }
+    ret
+}
+
+fn resolve_overlaps(digits: &HashMap<BTreeSet<char>, HashSet<u8>>) -> HashMap<BTreeSet<char>, u8> {
+    todo!()
+}
+
+fn unshuffle(input: &[String], output: &[String]) -> usize {
+    let mut results: HashMap<BTreeSet<char>, u8> = HashMap::new();
+    // segments -> candidate digits
+    let mut digits: HashMap<BTreeSet<char>, HashSet<u8>> = HashMap::new();
+    // 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 digits
+    // 6, 2, 5, 5, 4, 5, 6, 3, 7, 6 segments
+    // println!("Unshuffling: {:?} -> {:?}", input, output);
+    // LHS is sub-pattern of RHS
+    let overlap: HashMap<u8,Vec<u8>> = HashMap::from([
+        (0,vec![8]),
+        (1,vec![3,4,7,8,9]),
+        (2,vec![8]),
+    ]);
+    for val in input {
+        let candidates: Vec<u8> = match val.len() {
+            2 => vec![1],
+            3 => vec![7],
+            4 => vec![4],
+            5 => vec![2, 5, 3],
+            6 => vec![6, 9],
+            7 => vec![8],
+            _ => unreachable!(),
+        };
+        digits
+            .entry(val.chars().collect())
+            .or_default()
+            .extend(&candidates);
+    }
+    for _ in 0..10 {
+        // println!("===================");
+        // println!("D: {:?}", digits);
+        // println!("R: {:?}", results);
+        if results.len() == 10 {
+            break;
+        }
+        for (k, v) in &digits {
+            if v.len() == 1 {
+                let c = v.iter().copied().next().unwrap();
+                results.insert(k.clone(), c);
+            }
+        }
+        digits.values_mut().for_each(|v| {
+            for c in results.values() {
+                v.remove(c);
+            }
+        });
+        digits = digits.drain().filter(|(_, v)| !v.is_empty()).collect();
+    }
+    return 0;
+}
+
+#[aoc(day08, part1)] // 310
+pub fn solve_part1(input: &Data) -> usize {
+    input
+        .values()
+        .flatten()
+        .filter(|v| {
+            [2, 4, 3, 7].contains(&v.len())
+        })
+        .count()
+}
+
+#[aoc(day08, part2)]
+pub fn solve_part2(input: &Data) -> usize {
+    input.iter().map(|(k, v)| unshuffle(k, v)).sum()
+}

src/day09.rs

@@ -0,0 +1,103 @@
+use std::collections::{BTreeSet, VecDeque};
+
+use aoc_runner_derive::{aoc, aoc_generator};
+
+pub struct Data(Vec<Vec<u8>>);
+
+impl Data {
+    fn shape(&self) -> (usize, usize) {
+        if !self.0.iter().all(|v| v.len() == self.0[0].len()) {
+            panic!("Not rectangular!");
+        }
+        (self.0.len(), self.0[0].len())
+    }
+    fn get(&self, x: i64, y: i64) -> Option<u8> {
+        if x < 0 || y < 0 {
+            return None;
+        }
+        self.0
+            .get(x as usize)
+            .map(|v| v.get(y as usize).copied())
+            .flatten()
+    }
+}
+
+#[aoc_generator(day09)]
+pub fn input_generator(input: &str) -> Data {
+    Data(
+        input
+            .lines()
+            .map(|l| {
+                l.chars()
+                    .map(|c| c.to_digit(10).unwrap().try_into().unwrap())
+                    .collect()
+            })
+            .collect(),
+    )
+}
+
+fn get_low_points(input: &Data) -> Vec<(i64, i64, u8)> {
+    let mut ret = vec![];
+    let (sx, sy) = input.shape();
+    let sx = sx as i64;
+    let sy = sy as i64;
+    for x in 0..sx {
+        for y in 0..sy {
+            let c = input.get(x, y);
+            if c.is_none() {
+                continue;
+            }
+            let c = c.unwrap();
+            let low_point = input
+                .get(x + 1, y)
+                .iter()
+                .chain(input.get(x - 1, y).iter())
+                .chain(input.get(x, y + 1).iter())
+                .chain(input.get(x, y - 1).iter())
+                .all(|v| v > &c);
+            if low_point {
+                ret.push((x, y, c))
+            }
+        }
+    }
+    ret
+}
+
+#[aoc(day09, part1)] // 468
+pub fn solve_part1(input: &Data) -> usize {
+    get_low_points(input)
+        .iter()
+        .map(|(_, _, v)| (*v as usize) + 1)
+        .sum()
+}
+
+#[aoc(day09, part2)]
+pub fn solve_part2(input: &Data) -> usize {
+    let mut basins: BTreeSet<usize> = BTreeSet::new();
+    let mut q = VecDeque::new();
+    let mut visited = BTreeSet::<(i64, i64)>::new();
+    for (x, y, c) in &get_low_points(input) {
+        visited.clear();
+        q.clear();
+        q.push_back((*x, *y, *c));
+        while let Some((x, y, c)) = q.pop_front() {
+            if c == 9 || !visited.insert((x, y)) {
+                continue;
+            }
+            for d in [-1, 1] {
+                if let Some(v) = input.get(x + d, y) {
+                    if v > c {
+                        q.push_back((x + d, y, v));
+                    }
+                }
+                if let Some(v) = input.get(x, y + d) {
+                    if v > c {
+                        q.push_back((x, y + d, v));
+                    }
+                }
+            }
+        }
+        basins.insert(visited.len());
+    }
+    return basins.iter().rev().take(3).product();
+}

src/day10.rs

@@ -0,0 +1,66 @@
+use aoc_runner_derive::{aoc, aoc_generator};
+type Data = Vec<Vec<char>>;
+
+#[aoc_generator(day10)]
+pub fn input_generator(input: &str) -> Data {
+    input.lines().map(|l| l.chars().collect()).collect()
+}
+
+pub fn error_score(line: &Vec<char>) -> (usize,Vec<char>) {
+    let mut score=0;
+    let mut stack=vec![];
+    for c in line {
+        match c {
+            '(' => {stack.push(')')},
+            '[' => {stack.push(']')},
+            '{' => {stack.push('}')},
+            '<' => {stack.push('>')},
+            ')'|']'|'}'|'>' => {
+                if let Some(ex) = stack.pop() {
+                    if ex!=*c {
+                        score+=match c {
+                            ')' => 3,
+                            ']' => 57,
+                            '}' => 1197,
+                            '>' => 25137,
+                            c => unreachable!("Unexpected character {:?}!",c)
+                        };
+                        break;
+                    }
+                }
+            },
+            c => unreachable!("Unexpected character {:?}!",c)
+        }
+    }
+    (score,stack)
+}
+
+#[aoc(day10, part1)]
+pub fn solve_part1(input: &Data) -> usize {
+    input.iter().map(|v| error_score(v).0).sum()
+}
+
+#[aoc(day10, part2)]
+pub fn solve_part2(input: &Data) -> usize {
+    let mut scores=vec![];
+    for line in input {
+        let mut line_score=0;
+        let (error_score,mut stack) = error_score(line);
+        stack.reverse();
+        if error_score==0 && !stack.is_empty() {
+            for c in stack {
+                line_score*=5;
+                line_score+=match c {
+                    ')' => 1,
+                    ']' => 2,
+                    '}' => 3,
+                    '>' => 4,
+                    c => unreachable!("Unexpected character {:?}!",c)
+                }
+            }
+            scores.push(line_score);
+        }
+    }
+    scores.sort_unstable();
+    scores[scores.len()/2]
+}

src/lib.rs

@@ -1,6 +1,5 @@
 #![allow(clippy::clippy::needless_return)]
 #![feature(int_abs_diff)]
-
 use aoc_runner_derive::aoc_lib;
 pub mod day01;
 pub mod day02;
@@ -9,4 +8,7 @@ pub mod day04;
 pub mod day05;
 pub mod day06;
 pub mod day07;
+pub mod day08;
+pub mod day09;
+pub mod day10;
 aoc_lib! { year = 2021 }