Add day 22

Author: EbbDrop

benches/bench_days.rs

@@ -48,4 +48,4 @@ macro_rules! benches {
     };
 }
 
-benches!(21);
+benches!(22);

build.rs

@@ -194,16 +194,16 @@ fn press_number2(from_pos: Pos, to_pos: Pos, cache: &mut HashMap<(Pos, Pos, u32)
     }
 }
 
+#[allow(unused)]
 fn part2_inner(a: usize, b: usize, c: usize, cache: &mut HashMap<(Pos, Pos, u32), u64>) -> u64 {
     press_number2(keypad_pos(10), keypad_pos(a), cache)
         + press_number2(keypad_pos(a), keypad_pos(b), cache)
         + press_number2(keypad_pos(b), keypad_pos(c), cache)
         + press_number2(keypad_pos(c), keypad_pos(10), cache)
 }
 
-fn main() {
-    println!("cargo::rerun-if-changed=build.rs");
-
+#[allow(unused)]
+fn write_day21() {
     let mut lut = [0u64; 10usize.pow(3)];
 
     let mut cache = HashMap::new();
@@ -224,3 +224,35 @@ fn main() {
 
     file.write_all(&lut).unwrap();
 }
+
+// fn write_day22() {
+//     const MAX: u32 = 16777216;
+
+//     let mut lut = Vec::with_capacity(MAX as usize);
+
+//     for i in 0..MAX {
+//         let mut sn = i as u32;
+//         for _ in 0..2000 {
+//             sn = ((i * 64) % MAX) ^ i;
+//             sn = (sn / 32) ^ sn;
+//             sn = ((sn * 2048) % MAX) ^ sn;
+//         }
+
+//         lut[i as usize] = sn;
+//     }
+
+//     let mut path = PathBuf::from(std::env::var("OUT_DIR").unwrap());
+//     path.push("day22.bin");
+//     let mut file = File::create(path).unwrap();
+
+//     let lut: [u8; 4 * MAX as usize] = unsafe { transmute(lut) };
+
+//     file.write_all(&lut).unwrap();
+// }
+
+fn main() {
+    println!("cargo::rerun-if-changed=build.rs");
+
+    // write_day21();
+    // write_day22();
+}

src/day22.rs

@@ -0,0 +1,166 @@
+use core::str;
+
+use aoc_runner_derive::aoc;
+use bitvec::array::BitArray;
+
+const MAX: u32 = 16777216;
+
+// static LUT_P1: [u32; MAX as usize] =
+//     unsafe { transmute(*include_bytes!(concat!(env!("OUT_DIR"), "/day22.bin"))) };
+
+#[aoc(day22, part1)]
+pub fn part1(s: &str) -> u64 {
+    let s = s.as_bytes();
+
+    let mut sum = 0;
+    let mut i = 0;
+    unsafe {
+        while i < s.len() {
+            #[cfg(not(test))]
+            let mut sn = (*s.get_unchecked(i + 0) as u32) * 100000
+                + (*s.get_unchecked(i + 1) as u32) * 10000
+                + (*s.get_unchecked(i + 2) as u32) * 1000
+                + (*s.get_unchecked(i + 3) as u32) * 100
+                + (*s.get_unchecked(i + 4) as u32) * 10
+                + (*s.get_unchecked(i + 5) as u32) * 1
+                - (b'0' as u32 * 111_111);
+            #[cfg(not(test))]
+            {
+                i += 6;
+            }
+
+            #[cfg(test)]
+            let mut sn = 0;
+            while *s.get_unchecked(i) != b'\n' {
+                sn *= 10;
+                sn += (s.get_unchecked(i) - b'0') as u32;
+                i += 1;
+            }
+            i += 1;
+
+            for _ in 0..2000 {
+                sn = ((sn as u64 * 64) % MAX as u64) as u32 ^ sn;
+                sn = (sn / 32) ^ sn;
+                sn = ((sn as u64 * 2048) % MAX as u64) as u32 ^ sn;
+            }
+
+            sum += sn as u64;
+        }
+    }
+
+    sum
+}
+
+const SEQUENCES: usize = 18 << 15 | 18 << 10 | 18 << 5 | 18;
+
+#[aoc(day22, part2)]
+pub fn part2(s: &str) -> i16 {
+    let s = s.as_bytes();
+
+    let mut sequences = [0; SEQUENCES];
+    let mut done = BitArray::<[usize; SEQUENCES.div_ceil(usize::BITS as usize)]>::default();
+
+    let mut current_best = 0;
+
+    let mut i = 0;
+    unsafe {
+        while i < s.len() {
+            #[cfg(not(test))]
+            let mut sn = (*s.get_unchecked(i + 0) as u32) * 100000
+                + (*s.get_unchecked(i + 1) as u32) * 10000
+                + (*s.get_unchecked(i + 2) as u32) * 1000
+                + (*s.get_unchecked(i + 3) as u32) * 100
+                + (*s.get_unchecked(i + 4) as u32) * 10
+                + (*s.get_unchecked(i + 5) as u32) * 1
+                - (b'0' as u32 * 111_111);
+            #[cfg(not(test))]
+            {
+                i += 6;
+            }
+
+            #[cfg(test)]
+            let mut sn = 0;
+            while *s.get_unchecked(i) != b'\n' {
+                sn *= 10;
+                sn += (s.get_unchecked(i) - b'0') as u32;
+                i += 1;
+            }
+            i += 1;
+
+            let mut diffs = 0;
+            let mut prev = sn % 10;
+            for _ in 0..3 {
+                sn = ((sn as u64 * 64) % MAX as u64) as u32 ^ sn;
+                sn = (sn / 32) ^ sn;
+                sn = ((sn as u64 * 2048) % MAX as u64) as u32 ^ sn;
+                let price = sn % 10;
+                let diff = price + 9 - prev;
+                diffs = (diffs << 5) | diff;
+
+                prev = price;
+            }
+
+            for _ in 4..2000 {
+                sn = ((sn as u64 * 64) % MAX as u64) as u32 ^ sn;
+                sn = (sn / 32) ^ sn;
+                sn = ((sn as u64 * 2048) % MAX as u64) as u32 ^ sn;
+                let price = sn % 10;
+                let diff = price + 9 - prev;
+                diffs = ((diffs << 5) | diff) & 0xFFFFF;
+
+                if !done[diffs as usize] {
+                    sequences[diffs as usize] += price as i16;
+                    if current_best < sequences[diffs as usize] {
+                        current_best = sequences[diffs as usize];
+                    }
+                    done.set(diffs as usize, true);
+                }
+
+                prev = price;
+            }
+            done.fill(false);
+        }
+        // println!(
+        //     "{},{},{},{}",
+        //     (((current_best_i >> 15) & 0x1F) as i16) - 9,
+        //     (((current_best_i >> 10) & 0x1F) as i16) - 9,
+        //     (((current_best_i >> 05) & 0x1F) as i16) - 9,
+        //     (((current_best_i >> 00) & 0x1F) as i16) - 9,
+        // );
+        // println!("{}\n", sequences[current_best_i as usize]);
+
+        // println!(
+        //     "{}",
+        //     sequences[((-2 + 9) << 15 | (1 + 9) << 10 | (-1 + 9) << 05 | (3 + 9) << 00) as usize]
+        // );
+    }
+
+    current_best
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn example_part1() {
+        let s = r"1
+10
+100
+2024
+";
+
+        assert_eq!(part1(s), 37327623);
+    }
+
+    #[test]
+    fn example_part2() {
+        let s = r"1
+2
+3
+2024
+";
+
+        assert_eq!(part2(s), 23);
+    }
+}

src/lib.rs

@@ -16,6 +16,7 @@ pub mod day19;
 pub mod day2;
 pub mod day20;
 pub mod day21;
+pub mod day22;
 pub mod day3;
 pub mod day4;
 pub mod day5;

tests/test_days.rs

@@ -56,4 +56,5 @@ benches!(
     19 => ("267", "796449099271652"),
     20 => ("1511", "1020507"),
     21 => ("188398", "230049027535970"),
+    22 => ("20068964552", "2246"),
 );