add day 5, part 1

day05/common.rs

@@ -0,0 +1,154 @@
+// Copyright 2022 Christian Ulrich
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+use std::io;
+
+#[derive(Debug)]
+pub struct Stacks {
+    inner: Vec<Vec<char>>,
+}
+
+pub struct Moves {}
+
+#[derive(Debug)]
+pub struct Move {
+    count: usize,
+    from: usize,
+    to: usize,
+}
+
+impl Stacks {
+    pub fn from_stdin() -> Result<Self, &'static str> {
+        let mut stacks = vec![];
+        for line in io::stdin().lines() {
+            match Self::parse_line(&line.unwrap())? {
+                None => break,
+                Some(items) => {
+                    if items.len() != stacks.len() {
+                        if !stacks.is_empty() {
+                            return Err("input file contains invalid line");
+                        }
+                        stacks = vec![vec![]; items.len()];
+                    }
+                    for i in 0..items.len() {
+                        if let Some(item) = items[i] {
+                            stacks[i].push(item);
+                        }
+                    }
+                }
+            }
+        }
+        for stack in stacks.iter_mut() {
+            stack.reverse();
+        }
+        Ok(Self { inner: stacks })
+    }
+
+    fn parse_line(input: &str) -> Result<Option<Vec<Option<char>>>, &'static str> {
+        if input.starts_with(" 1 ") {
+            return Ok(None);
+        }
+        let mut result = vec![];
+        for chunk in input.chars().collect::<Vec<_>>().chunks(4) {
+            match chunk.iter().collect::<String>().as_str() {
+                "" => break,
+                item => result.push(Self::parse_item(item)?),
+            }
+        }
+        Ok(Some(result))
+    }
+
+    fn parse_item(input: &str) -> Result<Option<char>, &'static str> {
+        match input.trim() {
+            "" => return Ok(None),
+            item => {
+                if item.len() == 3
+                    && item.chars().nth(0).unwrap() == '['
+                    && item.chars().nth(2).unwrap() == ']'
+                {
+                    return Ok(item.chars().nth(1));
+                }
+            }
+        }
+        Err("cannot parse item")
+    }
+
+    pub fn move_items(&mut self, spec: Move) -> Result<(), &'static str> {
+        if spec.from >= self.inner.len()
+            || spec.to >= self.inner.len()
+            || spec.count > self.inner[spec.from].len()
+        {
+            return Err("invalid move");
+        }
+        for _ in 0..spec.count {
+            let item = self.inner[spec.from].pop().unwrap();
+            self.inner[spec.to].push(item);
+        }
+        Ok(())
+    }
+}
+
+impl Iterator for Stacks {
+    type Item = Vec<char>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        match self.inner.len() {
+            0 => None,
+            _ => Some(self.inner.remove(0)),
+        }
+    }
+}
+
+impl Move {
+    pub fn from_str(input: &str) -> Result<Self, &'static str> {
+        let parts = input.split(' ').collect::<Vec<_>>();
+        if parts.len() != 6 || parts[0] != "move" || parts[2] != "from" || parts[4] != "to" {
+            return Err("cannot parse move");
+        }
+        let from = match parts[3].parse::<usize>().map_err(|_| "cannot parse move")? {
+            value if { value > 0 } => Ok(value - 1),
+            _ => Err("integer out of range"),
+        };
+        let to = match parts[5].parse::<usize>().map_err(|_| "cannot parse move")? {
+            value if { value > 0 } => Ok(value - 1),
+            _ => Err("integer out of range"),
+        };
+        Ok(Self {
+            count: parts[1].parse().map_err(|_| "cannot parse integer")?,
+            from: from?,
+            to: to?,
+        })
+    }
+}
+
+impl Moves {
+    pub fn from_stdin() -> Self {
+        Self {}
+    }
+}
+
+impl Iterator for Moves {
+    type Item = Result<Move, &'static str>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        for line in io::stdin().lines() {
+            let line = line.unwrap();
+            if line.len() > 0 {
+                return Some(Move::from_str(&line));
+            }
+        }
+        None
+    }
+}

day05/input

@@ -0,0 +1,516 @@
+            [G] [W]         [Q]    
+[Z]         [Q] [M]     [J] [F]    
+[V]         [V] [S] [F] [N] [R]    
+[T]         [F] [C] [H] [F] [W] [P]
+[B] [L]     [L] [J] [C] [V] [D] [V]
+[J] [V] [F] [N] [T] [T] [C] [Z] [W]
+[G] [R] [Q] [H] [Q] [W] [Z] [G] [B]
+[R] [J] [S] [Z] [R] [S] [D] [L] [J]
+ 1   2   3   4   5   6   7   8   9 
+
+move 6 from 5 to 7
+move 2 from 9 to 1
+move 4 from 8 to 6
+move 1 from 8 to 1
+move 2 from 9 to 1
+move 1 from 6 to 1
+move 13 from 7 to 8
+move 1 from 2 to 8
+move 9 from 1 to 5
+move 1 from 3 to 8
+move 3 from 6 to 7
+move 4 from 4 to 1
+move 11 from 5 to 6
+move 6 from 6 to 9
+move 3 from 4 to 2
+move 7 from 8 to 6
+move 1 from 7 to 5
+move 1 from 4 to 3
+move 7 from 1 to 5
+move 2 from 2 to 7
+move 4 from 9 to 6
+move 1 from 3 to 6
+move 1 from 1 to 9
+move 1 from 3 to 6
+move 1 from 5 to 8
+move 4 from 6 to 7
+move 3 from 8 to 7
+move 7 from 5 to 7
+move 1 from 3 to 1
+move 1 from 2 to 6
+move 14 from 6 to 5
+move 2 from 5 to 2
+move 3 from 9 to 2
+move 6 from 2 to 9
+move 7 from 8 to 6
+move 7 from 7 to 3
+move 2 from 8 to 7
+move 6 from 3 to 7
+move 17 from 7 to 1
+move 1 from 3 to 1
+move 1 from 2 to 5
+move 4 from 5 to 6
+move 17 from 6 to 9
+move 7 from 9 to 4
+move 1 from 2 to 7
+move 2 from 5 to 4
+move 3 from 7 to 8
+move 7 from 5 to 2
+move 6 from 2 to 8
+move 8 from 9 to 6
+move 1 from 2 to 3
+move 8 from 4 to 9
+move 7 from 6 to 9
+move 18 from 1 to 7
+move 1 from 1 to 8
+move 2 from 6 to 9
+move 1 from 3 to 9
+move 1 from 4 to 6
+move 1 from 8 to 3
+move 1 from 3 to 1
+move 10 from 7 to 2
+move 9 from 8 to 4
+move 1 from 6 to 4
+move 2 from 7 to 8
+move 5 from 4 to 9
+move 17 from 9 to 5
+move 2 from 7 to 6
+move 5 from 9 to 7
+move 5 from 4 to 2
+move 8 from 2 to 4
+move 8 from 4 to 3
+move 2 from 6 to 5
+move 2 from 8 to 5
+move 3 from 9 to 3
+move 4 from 7 to 3
+move 6 from 9 to 6
+move 4 from 6 to 9
+move 5 from 9 to 3
+move 8 from 5 to 2
+move 1 from 1 to 9
+move 1 from 6 to 3
+move 1 from 9 to 4
+move 5 from 7 to 4
+move 19 from 3 to 1
+move 4 from 2 to 8
+move 13 from 5 to 1
+move 1 from 6 to 3
+move 3 from 3 to 6
+move 2 from 8 to 9
+move 4 from 2 to 9
+move 2 from 2 to 6
+move 1 from 1 to 6
+move 5 from 1 to 9
+move 10 from 9 to 3
+move 15 from 1 to 6
+move 21 from 6 to 2
+move 20 from 2 to 1
+move 2 from 8 to 9
+move 28 from 1 to 2
+move 6 from 4 to 6
+move 2 from 1 to 5
+move 3 from 3 to 4
+move 2 from 5 to 4
+move 1 from 4 to 3
+move 3 from 4 to 5
+move 2 from 5 to 4
+move 1 from 1 to 8
+move 25 from 2 to 9
+move 1 from 4 to 6
+move 1 from 3 to 8
+move 4 from 3 to 6
+move 1 from 4 to 9
+move 2 from 6 to 3
+move 1 from 5 to 9
+move 5 from 2 to 8
+move 7 from 9 to 6
+move 2 from 9 to 4
+move 3 from 2 to 1
+move 3 from 3 to 4
+move 1 from 3 to 5
+move 16 from 6 to 3
+move 7 from 8 to 3
+move 5 from 4 to 3
+move 1 from 1 to 3
+move 1 from 2 to 6
+move 1 from 5 to 6
+move 21 from 3 to 5
+move 2 from 1 to 2
+move 1 from 6 to 7
+move 10 from 9 to 8
+move 1 from 6 to 5
+move 5 from 8 to 7
+move 12 from 5 to 3
+move 20 from 3 to 6
+move 4 from 7 to 9
+move 1 from 7 to 3
+move 1 from 2 to 5
+move 1 from 3 to 8
+move 2 from 8 to 4
+move 4 from 8 to 7
+move 3 from 6 to 1
+move 1 from 1 to 5
+move 2 from 9 to 2
+move 2 from 1 to 5
+move 2 from 5 to 6
+move 3 from 7 to 1
+move 2 from 1 to 4
+move 4 from 6 to 8
+move 3 from 4 to 7
+move 3 from 2 to 5
+move 2 from 7 to 9
+move 9 from 9 to 8
+move 1 from 4 to 1
+move 7 from 5 to 7
+move 1 from 7 to 8
+move 1 from 3 to 1
+move 4 from 7 to 5
+move 2 from 1 to 9
+move 1 from 1 to 2
+move 5 from 5 to 4
+move 1 from 2 to 6
+move 5 from 7 to 9
+move 5 from 4 to 7
+move 11 from 9 to 6
+move 14 from 8 to 9
+move 23 from 6 to 5
+move 6 from 9 to 5
+move 1 from 6 to 2
+move 10 from 5 to 3
+move 1 from 4 to 9
+move 1 from 2 to 1
+move 2 from 7 to 3
+move 10 from 5 to 7
+move 8 from 5 to 2
+move 5 from 3 to 5
+move 7 from 5 to 8
+move 1 from 2 to 7
+move 9 from 7 to 9
+move 3 from 2 to 3
+move 2 from 6 to 2
+move 2 from 3 to 6
+move 4 from 7 to 5
+move 1 from 1 to 5
+move 4 from 3 to 1
+move 2 from 5 to 2
+move 1 from 3 to 2
+move 2 from 6 to 8
+move 7 from 5 to 3
+move 9 from 2 to 4
+move 2 from 1 to 2
+move 2 from 5 to 3
+move 1 from 4 to 9
+move 1 from 6 to 9
+move 1 from 4 to 2
+move 2 from 1 to 7
+move 3 from 2 to 6
+move 4 from 8 to 7
+move 2 from 8 to 3
+move 2 from 3 to 7
+move 1 from 6 to 5
+move 2 from 8 to 2
+move 5 from 4 to 1
+move 8 from 9 to 8
+move 1 from 5 to 7
+move 10 from 9 to 2
+move 8 from 8 to 2
+move 1 from 1 to 6
+move 12 from 3 to 9
+move 7 from 7 to 4
+move 13 from 2 to 4
+move 7 from 2 to 7
+move 1 from 6 to 7
+move 3 from 9 to 8
+move 2 from 6 to 3
+move 1 from 3 to 2
+move 1 from 3 to 9
+move 3 from 1 to 5
+move 1 from 1 to 6
+move 4 from 7 to 6
+move 5 from 7 to 1
+move 1 from 2 to 1
+move 6 from 9 to 4
+move 5 from 9 to 7
+move 3 from 8 to 3
+move 22 from 4 to 9
+move 24 from 9 to 8
+move 1 from 9 to 2
+move 2 from 4 to 3
+move 10 from 8 to 3
+move 1 from 2 to 1
+move 1 from 3 to 8
+move 1 from 6 to 3
+move 1 from 1 to 4
+move 4 from 3 to 4
+move 4 from 6 to 1
+move 2 from 4 to 5
+move 4 from 7 to 2
+move 7 from 4 to 6
+move 4 from 6 to 1
+move 2 from 6 to 3
+move 1 from 6 to 2
+move 5 from 5 to 2
+move 12 from 3 to 5
+move 3 from 7 to 8
+move 6 from 2 to 3
+move 11 from 1 to 9
+move 1 from 1 to 7
+move 1 from 7 to 5
+move 2 from 3 to 9
+move 2 from 9 to 7
+move 4 from 2 to 5
+move 2 from 7 to 1
+move 17 from 8 to 1
+move 1 from 3 to 2
+move 16 from 1 to 3
+move 8 from 3 to 4
+move 2 from 8 to 3
+move 2 from 1 to 5
+move 1 from 2 to 6
+move 12 from 5 to 8
+move 1 from 6 to 3
+move 9 from 3 to 9
+move 8 from 4 to 6
+move 2 from 1 to 6
+move 6 from 8 to 4
+move 3 from 4 to 6
+move 1 from 1 to 9
+move 11 from 6 to 8
+move 3 from 4 to 3
+move 17 from 9 to 5
+move 2 from 6 to 7
+move 1 from 9 to 1
+move 2 from 8 to 6
+move 1 from 7 to 5
+move 1 from 8 to 9
+move 1 from 1 to 7
+move 3 from 9 to 6
+move 2 from 7 to 8
+move 1 from 9 to 6
+move 15 from 5 to 2
+move 9 from 3 to 9
+move 11 from 8 to 3
+move 6 from 9 to 8
+move 4 from 6 to 7
+move 3 from 3 to 7
+move 5 from 5 to 6
+move 7 from 7 to 5
+move 3 from 6 to 1
+move 2 from 1 to 4
+move 1 from 9 to 2
+move 2 from 9 to 3
+move 2 from 6 to 3
+move 1 from 1 to 8
+move 6 from 5 to 9
+move 8 from 2 to 5
+move 10 from 8 to 5
+move 1 from 2 to 9
+move 21 from 5 to 9
+move 2 from 8 to 4
+move 5 from 9 to 1
+move 2 from 5 to 2
+move 15 from 9 to 2
+move 1 from 5 to 9
+move 9 from 9 to 3
+move 1 from 1 to 6
+move 3 from 4 to 1
+move 20 from 3 to 5
+move 20 from 5 to 4
+move 7 from 4 to 3
+move 1 from 1 to 7
+move 11 from 4 to 5
+move 4 from 3 to 2
+move 11 from 5 to 4
+move 2 from 6 to 7
+move 4 from 3 to 9
+move 2 from 2 to 8
+move 2 from 9 to 4
+move 6 from 4 to 6
+move 2 from 7 to 9
+move 1 from 7 to 6
+move 1 from 4 to 9
+move 4 from 4 to 6
+move 2 from 8 to 6
+move 1 from 4 to 3
+move 1 from 4 to 6
+move 1 from 3 to 1
+move 3 from 4 to 3
+move 9 from 2 to 8
+move 2 from 3 to 7
+move 5 from 6 to 2
+move 2 from 7 to 5
+move 1 from 5 to 2
+move 1 from 9 to 3
+move 1 from 5 to 1
+move 13 from 2 to 5
+move 4 from 9 to 5
+move 1 from 3 to 4
+move 9 from 2 to 3
+move 7 from 3 to 2
+move 11 from 5 to 6
+move 5 from 8 to 7
+move 1 from 3 to 1
+move 2 from 8 to 5
+move 2 from 8 to 1
+move 1 from 4 to 1
+move 6 from 2 to 7
+move 3 from 5 to 3
+move 1 from 2 to 5
+move 7 from 7 to 9
+move 3 from 3 to 5
+move 1 from 2 to 5
+move 2 from 3 to 2
+move 6 from 1 to 7
+move 10 from 7 to 3
+move 1 from 2 to 3
+move 6 from 9 to 8
+move 1 from 2 to 4
+move 2 from 6 to 1
+move 5 from 1 to 9
+move 8 from 5 to 8
+move 2 from 1 to 6
+move 6 from 3 to 4
+move 1 from 5 to 3
+move 4 from 9 to 6
+move 1 from 1 to 4
+move 2 from 9 to 2
+move 5 from 6 to 1
+move 11 from 6 to 7
+move 1 from 2 to 8
+move 6 from 7 to 5
+move 10 from 8 to 4
+move 2 from 3 to 9
+move 3 from 3 to 5
+move 4 from 7 to 9
+move 2 from 1 to 3
+move 10 from 5 to 8
+move 6 from 6 to 1
+move 2 from 6 to 8
+move 2 from 9 to 5
+move 4 from 9 to 6
+move 7 from 4 to 8
+move 5 from 6 to 1
+move 4 from 8 to 2
+move 2 from 5 to 6
+move 5 from 4 to 5
+move 1 from 7 to 5
+move 2 from 3 to 6
+move 1 from 3 to 8
+move 4 from 6 to 1
+move 4 from 2 to 3
+move 5 from 5 to 1
+move 2 from 3 to 2
+move 2 from 3 to 2
+move 20 from 8 to 2
+move 5 from 4 to 8
+move 1 from 4 to 3
+move 8 from 2 to 1
+move 1 from 5 to 6
+move 5 from 2 to 3
+move 1 from 6 to 5
+move 5 from 3 to 2
+move 1 from 3 to 7
+move 6 from 8 to 5
+move 13 from 2 to 9
+move 7 from 9 to 8
+move 1 from 7 to 8
+move 5 from 8 to 3
+move 2 from 2 to 5
+move 2 from 8 to 4
+move 27 from 1 to 5
+move 1 from 2 to 3
+move 5 from 3 to 1
+move 22 from 5 to 7
+move 1 from 8 to 5
+move 1 from 3 to 2
+move 7 from 1 to 3
+move 2 from 3 to 7
+move 2 from 2 to 4
+move 5 from 9 to 1
+move 5 from 3 to 9
+move 3 from 1 to 5
+move 3 from 1 to 6
+move 3 from 6 to 3
+move 4 from 4 to 2
+move 8 from 5 to 3
+move 8 from 7 to 4
+move 14 from 7 to 4
+move 1 from 1 to 7
+move 6 from 9 to 6
+move 7 from 5 to 3
+move 14 from 3 to 6
+move 2 from 2 to 1
+move 4 from 3 to 7
+move 6 from 7 to 6
+move 1 from 7 to 6
+move 1 from 5 to 1
+move 2 from 1 to 5
+move 3 from 5 to 7
+move 8 from 6 to 5
+move 5 from 5 to 1
+move 1 from 7 to 3
+move 1 from 3 to 8
+move 22 from 4 to 7
+move 7 from 6 to 3
+move 4 from 3 to 2
+move 3 from 1 to 3
+move 17 from 7 to 6
+move 1 from 8 to 1
+move 2 from 2 to 4
+move 3 from 7 to 2
+move 2 from 2 to 9
+move 1 from 1 to 8
+move 2 from 3 to 1
+move 6 from 6 to 8
+move 2 from 9 to 2
+move 4 from 5 to 1
+move 5 from 8 to 9
+move 1 from 7 to 3
+move 4 from 3 to 4
+move 1 from 7 to 4
+move 4 from 9 to 7
+move 5 from 7 to 9
+move 1 from 7 to 3
+move 2 from 2 to 8
+move 5 from 4 to 2
+move 21 from 6 to 8
+move 2 from 3 to 8
+move 23 from 8 to 6
+move 1 from 2 to 6
+move 2 from 9 to 8
+move 22 from 6 to 7
+move 2 from 9 to 3
+move 2 from 3 to 7
+move 2 from 1 to 6
+move 1 from 2 to 5
+move 3 from 1 to 3
+move 6 from 7 to 4
+move 5 from 8 to 5
+move 1 from 3 to 8
+move 1 from 9 to 3
+move 6 from 4 to 8
+move 1 from 5 to 3
+move 6 from 2 to 8
+move 15 from 7 to 5
+move 1 from 7 to 1
+move 14 from 5 to 8
+move 1 from 4 to 9
+move 5 from 1 to 7
+move 3 from 6 to 2
+move 4 from 5 to 6
+move 1 from 4 to 8
+move 4 from 3 to 1
+move 2 from 9 to 2
+move 7 from 7 to 1
+move 7 from 2 to 7
+move 9 from 8 to 6
+move 7 from 7 to 1
+move 12 from 6 to 8
+move 25 from 8 to 6
+move 3 from 8 to 1
+move 28 from 6 to 2
+move 15 from 2 to 3
+move 1 from 5 to 4
+move 3 from 2 to 7
+move 6 from 2 to 9
+

day05/part1.rs

@@ -0,0 +1,32 @@
+// Copyright 2022 Christian Ulrich
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+// usage: ./part1 < input
+
+pub mod common;
+
+use common::{Moves, Stacks};
+
+fn main() -> Result<(), &'static str> {
+    let mut stacks = Stacks::from_stdin()?;
+    for op in Moves::from_stdin() {
+        stacks.move_items(op?)?;
+    }
+    let result: Result<String, _> = stacks
+        .map(|s| s.last().cloned().ok_or("at least one stack is empty"))
+        .collect();
+    println!("{}", result?);
+    Ok(())
+}

day05/testinput

@@ -0,0 +1,9 @@
+    [D]    
+[N] [C]    
+[Z] [M] [P]
+ 1   2   3 
+
+move 1 from 2 to 1
+move 3 from 1 to 3
+move 2 from 2 to 1
+move 1 from 1 to 2