Day 18 basic parse/Display implementations.

This commit is contained in:
Bill Thiede 2021-12-21 14:07:17 -08:00
parent 7a3a9c096a
commit 247e4a89a5
3 changed files with 333 additions and 0 deletions

100
2021/input/2021/day18.txt Normal file
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@ -0,0 +1,100 @@
[[2,[2,[4,0]]],[6,1]]
[[3,[4,[2,4]]],[[6,9],[6,1]]]
[7,[8,[8,[0,8]]]]
[[[[2,9],5],5],[[[0,1],8],[[7,9],5]]]
[[[[3,0],[7,0]],[[9,6],[1,9]]],4]
[[[0,[4,8]],8],[[[2,1],9],6]]
[[[5,[7,7]],[[9,6],2]],[[[5,8],8],0]]
[[0,3],[[8,2],[6,[2,2]]]]
[[[9,0],[4,[4,7]]],[7,[[9,1],9]]]
[0,[7,[1,1]]]
[[[4,[0,1]],[[1,0],8]],[[[3,9],[0,1]],[[9,1],[8,8]]]]
[[[6,0],3],2]
[[[[4,1],[2,7]],[9,[8,9]]],[[3,0],0]]
[[[[2,4],[8,7]],[9,[9,7]]],[[[2,5],6],9]]
[[7,6],[[4,[2,4]],[3,8]]]
[[7,2],[[8,8],7]]
[[[[6,0],4],[[4,7],4]],[[6,[2,7]],[[6,5],3]]]
[[[[8,8],[7,6]],4],5]
[[0,[[6,9],[7,9]]],[9,5]]
[9,[[[0,4],6],[[7,0],0]]]
[[[[4,4],0],[3,[3,9]]],[[7,5],[5,[7,2]]]]
[[[8,3],[[8,5],[4,4]]],[0,[0,3]]]
[[9,[3,[6,7]]],[[7,0],[[9,2],7]]]
[[[3,7],[[3,6],9]],7]
[[2,[2,[5,7]]],[[[6,4],5],[4,7]]]
[[[[9,0],2],[[4,4],6]],[[[3,2],[5,5]],[[5,9],7]]]
[[[[2,5],4],[8,5]],6]
[[[3,2],[[1,7],5]],[[8,1],[1,[1,2]]]]
[8,[[3,[5,4]],5]]
[[[2,[5,9]],[1,3]],[[[2,3],[8,3]],[[5,1],[8,9]]]]
[[[2,0],[[3,3],[4,7]]],[[[8,7],[7,4]],1]]
[[[[7,4],9],[3,[4,1]]],[[[8,4],5],7]]
[[[[0,2],9],3],[9,[5,3]]]
[3,4]
[[[1,[0,2]],[[9,9],[8,2]]],6]
[[[[2,9],[3,5]],9],[[9,3],[3,[6,7]]]]
[[0,[[4,6],4]],[2,[5,2]]]
[9,[[9,[6,8]],8]]
[3,[[[1,2],[0,9]],[[4,9],1]]]
[[[[8,7],[1,7]],[[2,6],[8,5]]],[3,[[8,0],[6,9]]]]
[[8,[[4,9],7]],[3,[9,4]]]
[[0,[[3,2],[2,2]]],0]
[[[2,7],[[5,7],4]],[[[6,0],[2,1]],[[4,1],[1,6]]]]
[[[[9,6],[0,3]],[[0,6],[0,4]]],[[[3,7],[6,7]],7]]
[[[[1,1],6],[[5,6],4]],[[5,[0,7]],1]]
[[[3,9],[[7,3],[1,5]]],[[[1,2],3],[0,[5,6]]]]
[[[[4,4],[0,5]],6],[[7,[2,0]],6]]
[[[[2,2],6],9],[[[9,1],2],[[8,6],8]]]
[[[[5,0],8],[[5,7],7]],[6,[5,3]]]
[[[[8,2],[8,4]],1],[[1,[7,3]],8]]
[[[[3,2],2],[[4,9],[5,4]]],[[[9,2],4],[5,[6,0]]]]
[[1,[[0,6],0]],[[[1,5],2],[[6,0],[3,7]]]]
[4,[7,[6,[3,3]]]]
[[[0,[2,5]],2],5]
[[[0,[5,7]],9],[[[2,3],[3,4]],[[0,4],9]]]
[[3,1],[[[4,1],9],[[0,5],[8,6]]]]
[[9,[2,0]],[[0,[1,7]],[9,[6,4]]]]
[[[[6,5],5],5],[5,8]]
[[[[2,8],[1,3]],[[5,4],2]],[[[0,8],[5,1]],[9,[5,6]]]]
[[[[6,9],7],[9,7]],2]
[[[[1,7],8],[8,7]],[[[3,5],4],8]]
[[[[1,8],[1,0]],0],[[7,1],5]]
[[[9,[6,8]],3],[[5,1],[4,[8,2]]]]
[[[0,[2,1]],1],[3,[9,[5,5]]]]
[[2,5],[2,5]]
[[[[1,1],[8,3]],[[1,9],[4,9]]],[[5,[4,8]],[[5,0],0]]]
[[[0,7],[[3,4],1]],[[[1,2],[2,9]],[[2,0],9]]]
[3,2]
[[[9,[8,2]],[7,3]],7]
[[[[6,9],9],[3,2]],0]
[[3,[[6,1],8]],6]
[[[[5,9],9],[[4,4],7]],[7,5]]
[1,[[2,8],0]]
[[2,[0,6]],[[[3,3],[0,4]],8]]
[[[[4,8],9],[0,[3,0]]],[[0,[3,1]],[8,[7,4]]]]
[[[6,[8,0]],[0,[8,9]]],[3,8]]
[[[[0,8],[9,4]],[1,[2,0]]],1]
[[7,6],[[[0,2],9],3]]
[[[[1,0],3],2],1]
[[[[1,2],8],5],7]
[0,[[3,0],7]]
[[7,[[0,9],[8,4]]],[[2,0],[[2,8],1]]]
[[[1,8],[[8,1],1]],[3,[8,9]]]
[4,[[3,7],[[5,2],9]]]
[[[[3,8],[2,9]],[3,9]],[[[3,7],[6,9]],[[1,7],2]]]
[9,[[[3,7],9],[[4,9],[8,6]]]]
[[7,[3,9]],[0,7]]
[[[1,6],0],[[7,[8,1]],[6,3]]]
[[[[3,9],3],[[2,6],[8,0]]],[[3,3],9]]
[[[1,2],[1,6]],[[1,[4,2]],0]]
[[[0,[3,0]],2],[[7,[9,4]],[6,8]]]
[6,[[[3,1],1],5]]
[[[3,4],[[5,9],[1,1]]],[[2,[0,1]],3]]
[[2,[[1,5],7]],[0,2]]
[[1,[[6,7],7]],4]
[6,[5,[[3,2],[6,8]]]]
[[[3,9],[[4,0],6]],[8,[3,[5,2]]]]
[[5,[[7,3],[2,2]]],[[7,7],7]]
[[[1,2],[[2,4],[6,1]]],[[0,[4,2]],[[5,7],[2,3]]]]
[[[8,7],8],[[7,[3,6]],[[1,0],4]]]

232
2021/src/day18.rs Normal file
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use advent::prelude::*;
use aoc_runner_derive::{aoc, aoc_generator};
use std::io::Read;
#[derive(Debug, PartialEq)]
enum ChildType {
None,
Value(usize),
Subtree(Idx),
}
#[derive(Copy, Clone, Debug, Default, PartialEq)]
struct Idx(usize);
#[derive(Debug, PartialEq)]
struct Node {
idx: Idx,
parent: Option<Idx>,
left: ChildType,
right: ChildType,
}
// Tree needs to support merging two into one for adding snailfish numbers.
// Tree needs to support rightward and leftward depth first searches to find neighbors for applying
// exploded spill over.
// Need to support remove and/or replace for explode.
// Need to support insert and/or replace for split.
#[derive(Debug, Default, PartialEq)]
struct Tree {
root: Idx,
nodes: Vec<Node>,
}
fn read_byte<R: Read>(reader: &mut R) -> std::io::Result<Option<u8>> {
reader.bytes().next().transpose()
}
impl Tree {
fn find_root(&self, node: &Node) -> Idx {
match node.parent {
Some(parent_idx) => self.find_root(&self[parent_idx]),
None => node.idx,
}
}
fn add_node(&mut self, left: ChildType, right: ChildType) -> Idx {
let idx = Idx(self.nodes.len());
self.nodes.push(Node {
idx,
parent: None,
left,
right,
});
idx
}
fn from_str_node<R: Read>(&mut self, r: &mut R) -> ChildType {
let mut parsing_left = true;
// Can this be rewritten to eliminate the need for `None`?
let mut left = ChildType::None;
let mut right = ChildType::None;
while let Ok(Some(b)) = read_byte(r) {
match b {
b'[' => {
let node = self.from_str_node(r);
if parsing_left {
left = node;
} else {
right = node;
}
}
b']' => {
let mut left_idx = None;
let mut right_idx = None;
if let ChildType::Subtree(idx) = left {
left_idx = Some(idx);
}
if let ChildType::Subtree(idx) = right {
right_idx = Some(idx);
}
let child_idx = self.add_node(left, right);
if let Some(idx) = left_idx {
self[idx].parent = Some(child_idx);
}
if let Some(idx) = right_idx {
self[idx].parent = Some(child_idx);
}
return ChildType::Subtree(child_idx);
}
b',' => parsing_left = false,
b'0'..=b'9' => {
let v = dbg!(b - b'0');
if parsing_left {
left = ChildType::Value(v.into());
parsing_left = false;
} else {
right = ChildType::Value(v.into());
}
continue;
}
_ => panic!("unknown byte '{}'", b),
}
}
unreachable!()
}
fn fmt_node(&self, f: &mut Formatter<'_>, node: &Node) -> std::fmt::Result {
write!(f, "[")?;
match node.left {
ChildType::None => panic!("left node was None"),
ChildType::Value(v) => write!(f, "{}", v),
ChildType::Subtree(idx) => self.fmt_node(f, &self[idx]),
};
write!(f, ",")?;
match node.right {
ChildType::None => panic!("right node was None"),
ChildType::Value(v) => write!(f, "{}", v),
ChildType::Subtree(idx) => self.fmt_node(f, &self[idx]),
};
write!(f, "]")?;
Ok(())
}
}
impl FromStr for Tree {
type Err = Infallible;
fn from_str(input: &str) -> std::result::Result<Tree, Infallible> {
let mut tree = Tree::default();
let mut bytes = input.as_bytes();
assert_eq!(
read_byte(&mut bytes).expect("couldn't read first byte"),
Some(b'[')
);
tree.from_str_node(&mut bytes);
tree.root = tree.find_root(&tree[Idx(0)]);
Ok(tree)
}
}
impl Index<Idx> for Tree {
type Output = Node;
fn index(&self, idx: Idx) -> &Self::Output {
&self.nodes[idx.0]
}
}
impl IndexMut<Idx> for Tree {
fn index_mut(&mut self, idx: Idx) -> &mut Self::Output {
&mut self.nodes[idx.0]
}
}
impl Display for Tree {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
if self.nodes.is_empty() {
return write!(f, "[]");
}
let node = &self[self.root];
self.fmt_node(f, &node)?;
Ok(())
}
}
#[aoc(day18, part1)]
fn part1(input: &str) -> Result<usize> {
for l in input.lines() {
let tree: Tree = l.parse()?;
dbg!(&tree);
}
Ok(0)
}
/*
#[aoc(day18, part2)]
fn part2(input: &str) -> Result<usize> {
todo!("part2");
Ok(0)
}
*/
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_display() -> Result<()> {
for (i, s) in ["[1,2]", "[[1,2],3]", "[1,[2,3]]", "[[1,2],[3,4]]"]
.into_iter()
.enumerate()
{
let t = s.parse::<Tree>()?;
assert_eq!(&t.to_string(), s, "input {}: '{}'", i, s);
//assert_eq!(&t.to_string(), s, "input {}: '{}'\ntree: {:#?}", i, s, t);
}
Ok(())
}
//#[test]
fn test_part1() -> Result<()> {
let sum = [
[[[6, 6], [7, 6]], [[7, 7], [7, 0]]],
[[[7, 7], [7, 7]], [[7, 8], [9, 9]]],
];
dbg!(&sum);
let input = r#"
[[[0,[5,8]],[[1,7],[9,6]]],[[4,[1,2]],[[1,4],2]]]
[[[5,[2,8]],4],[5,[[9,9],0]]]
[6,[[[6,2],[5,6]],[[7,6],[4,7]]]]
[[[6,[0,7]],[0,9]],[4,[9,[9,0]]]]
[[[7,[6,4]],[3,[1,3]]],[[[5,5],1],9]]
[[6,[[7,3],[3,2]]],[[[3,8],[5,7]],4]]
[[[[5,4],[7,7]],8],[[8,3],8]]
[[9,3],[[9,9],[6,[4,9]]]]
[[2,[[7,7],7]],[[5,8],[[9,3],[0,2]]]]
[[[[5,2],5],[8,[3,7]]],[[5,[7,5]],[4,4]]]
"#
.trim();
assert_eq!(part1(input)?, 4140);
Ok(())
}
/*
#[test]
fn test_part2()->Result<()> {
let input = r#"
"#
.trim();
assert_eq!(part2(input)?, usize::MAX);
Ok(())
}
*/
}

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@ -7,6 +7,7 @@ pub mod day13;
pub mod day15;
pub mod day16;
pub mod day17;
pub mod day18;
pub mod day2;
pub mod day3;
pub mod day4;