Add 2022/21/1

2022/src/bin/day21.rs

@@ -0,0 +1,93 @@
+#![feature(test, try_blocks, hash_drain_filter)]
+extern crate test;
+use aoc2022::{boilerplate, common::*};
+use fnv::FnvHashMap as HashMap;
+
+const DAY: usize = 21;
+type Parsed<'a> = HashMap<&'a [u8], Monkey<'a>>;
+
+#[derive(Clone, Copy)]
+enum Monkey<'a> {
+    Number(isize),
+    Add(&'a [u8], &'a [u8]),
+    Sub(&'a [u8], &'a [u8]),
+    Mul(&'a [u8], &'a [u8]),
+    Div(&'a [u8], &'a [u8]),
+}
+
+fn parse_input(raw: &str) -> Parsed {
+    raw.lines()
+        .map(|line| {
+            let key = &line.as_bytes()[0..4];
+            let value = line[6..].as_bytes();
+
+            if value[0].is_ascii_digit() {
+                return (key, Monkey::Number(parse_num(&line[6..])));
+            }
+            match value[5] {
+                b'+' => (key, Monkey::Add(&value[0..4], &value[7..])),
+                b'-' => (key, Monkey::Sub(&value[0..4], &value[7..])),
+                b'*' => (key, Monkey::Mul(&value[0..4], &value[7..])),
+                b'/' => (key, Monkey::Div(&value[0..4], &value[7..])),
+                _ => unreachable!(),
+            }
+        })
+        .collect()
+}
+
+fn part1(parsed: &Parsed) -> isize {
+    let mut missing = parsed.clone();
+    let mut resolved = HashMap::<&[u8], isize>::default();
+    // parsed.iter().filter_map(|(&k, m)| if let Monkey::Number(n) = m { Some((k, *n)) } else { None }).collect();
+    while !missing.is_empty() {
+        missing
+            .drain_filter(|&k, v| {
+                let o: Option<()> = try {
+                    resolved.insert(
+                        k,
+                        match v {
+                            Monkey::Number(n) => *n,
+                            Monkey::Add(a, b) => resolved.get(a)? + resolved.get(b)?,
+                            Monkey::Sub(a, b) => resolved.get(a)? - resolved.get(b)?,
+                            Monkey::Mul(a, b) => resolved.get(a)? * resolved.get(b)?,
+                            Monkey::Div(a, b) => resolved.get(a)? / resolved.get(b)?,
+                        },
+                    );
+                };
+                o.is_some()
+            })
+            .last();
+    }
+    let root: &[u8] = b"root";
+    resolved[root]
+}
+
+fn part2(parsed: &Parsed) -> usize {
+    unimplemented!()
+}
+
+boilerplate! {
+    TEST_INPUT == "\
+root: pppw + sjmn
+dbpl: 5
+cczh: sllz + lgvd
+zczc: 2
+ptdq: humn - dvpt
+dvpt: 3
+lfqf: 4
+humn: 5
+ljgn: 2
+sjmn: drzm * dbpl
+sllz: 4
+pppw: cczh / lfqf
+lgvd: ljgn * ptdq
+drzm: hmdt - zczc
+hmdt: 32",
+    tests: {
+        part1: { TEST_INPUT => 152 },
+        part2: { TEST_INPUT => 301 },
+    },
+    bench1 == 66174565793494,
+    bench2 == 0,
+    bench_parse: HashMap::len => 1901,
+}