This commit is contained in:
Daniel S. 2020-12-15 00:35:08 +01:00
parent d9e4bf6ad3
commit 849cc76034
2 changed files with 171 additions and 0 deletions

170
src/day14.rs Normal file
View file

@ -0,0 +1,170 @@
use aoc_runner_derive::{aoc, aoc_generator};
use std::collections::HashMap;
#[derive(Debug, Clone)]
pub enum Command {
Mask { and: u64, or: u64, raw: Vec<char> },
Write { val: u64, addr: u64 },
}
#[inline(always)]
fn set_bit(v: u64, bit: usize, val: bool) -> u64 {
let mut v = v;
let bv = 1 << bit;
if val {
v |= bv;
} else {
v &= !bv;
}
return v;
}
impl Command {
fn apply_mask_v1(&self, val: u64) -> u64 {
if let Command::Mask { and, or, .. } = self {
return (val & and) | or;
};
panic!("Can't apply non-mask command");
}
fn apply_mask_v2_inner(&self, addr: &mut u64, s: &Vec<char>, ret: &mut Vec<u64>) {
let mut s_c = s.clone();
for (idx, c) in s.iter().enumerate() {
match *c {
'0' => (),
'1' => {
*addr = set_bit(*addr, idx, true);
}
'X' => {
s_c[idx] = '0';
*addr = set_bit(*addr, idx, true);
self.apply_mask_v2_inner(addr, &s_c, ret);
*addr = set_bit(*addr, idx, false);
self.apply_mask_v2_inner(addr, &s_c, ret);
}
_ => unreachable!(),
}
}
ret.push(*addr);
}
fn apply_mask_v2(&self, addr: u64) -> Vec<u64> {
let mut addr = addr;
if let Command::Mask { raw, .. } = self {
let mut raw = raw.clone();
raw.reverse();
let mut ret = vec![];
self.apply_mask_v2_inner(&mut addr, &raw, &mut ret);
ret.sort();
ret.dedup();
return ret;
};
panic!("Can't apply non-mask command");
}
}
type Data = Vec<Command>;
#[aoc_generator(day14)]
pub fn input_generator(input: &str) -> Data {
let mut ret = vec![];
for line in input.lines() {
if line.starts_with("mask") {
let mut mask_and = 0;
let mut mask_or = 0;
let mut char_buf = vec![];
for (n, c) in line.split("=").nth(1).unwrap().trim().chars().enumerate() {
char_buf.push(c);
mask_and <<= 1;
mask_or <<= 1;
match c {
'X' => {
mask_and |= 1;
mask_or |= 0;
}
'1' => {
mask_and |= 1;
mask_or |= 1;
}
'0' => {
mask_and |= 0;
mask_or |= 0;
}
c => {
panic!("Invalid char in mask: {}", c);
}
}
}
ret.push(Command::Mask {
and: mask_and,
or: mask_or,
raw: char_buf,
});
continue;
}
if line.starts_with("mem") {
let addr: u64 = line
.chars()
.skip_while(|&c| c != '[')
.skip(1)
.take_while(|&c| c != ']')
.collect::<String>()
.parse()
.unwrap();
let val: u64 = line
.chars()
.skip_while(|&c| c != '=')
.skip(1)
.skip_while(|&c| c.is_whitespace())
.collect::<String>()
.parse()
.unwrap();
ret.push(Command::Write { addr, val });
}
}
ret
}
#[aoc(day14, part1)]
pub fn solve_part1(input: &Data) -> u64 {
let mut mem = HashMap::new();
let mut mask = Command::Mask {
and: std::u64::MAX,
or: 0u64,
raw: vec![],
};
for inst in input {
match inst {
Command::Write { val, addr } => {
mem.insert(*addr, mask.apply_mask_v1(*val));
}
m => {
mask = m.clone();
}
}
}
return mem.values().copied().sum();
}
#[aoc(day14, part2)]
pub fn solve_part2(input: &Data) -> u64 {
let mut mem = HashMap::new();
let mut mask = Command::Mask {
and: std::u64::MAX,
or: 0u64,
raw: vec![],
};
for inst in input {
match inst {
Command::Write { val, addr } => {
for addr in mask.apply_mask_v2(*addr) {
mem.insert(addr, val);
}
}
m => {
mask = m.clone();
}
}
}
return mem.values().copied().sum();
}

View file

@ -12,4 +12,5 @@ pub mod day10;
pub mod day11; pub mod day11;
pub mod day12; pub mod day12;
pub mod day13; pub mod day13;
pub mod day14;
aoc_lib! { year = 2020 } aoc_lib! { year = 2020 }