day22: part 1 solution

src/day22.rs

@@ -0,0 +1,64 @@
+use aoc_runner_derive::{aoc, aoc_generator};
+
+fn evolve_secret(mut n: i64) -> i64 {
+    n = ((n * 64) ^ n) % 16777216;
+    n = ((n / 32) ^ n) % 16777216;
+    n = ((n * 2048) ^ n)  % 16777216;
+    n
+}
+
+fn rounds(mut secret: i64, n: i64) -> i64 {
+    for _ in 0..n {
+        secret = evolve_secret(secret)
+    }
+    secret
+}
+
+fn parse(input: &str) -> Vec<i64> {
+    input.lines().map(|l| l.parse().unwrap()).collect()
+}
+
+#[aoc(day22, part1)]
+fn part1(input: &str) -> i64 {
+    let secrets = parse(input);
+
+    secrets.iter().map(|s| rounds(*s, 2000)).sum::<i64>()
+}
+
+#[aoc(day22, part2)]
+fn part2(input: &str) -> i64 {
+    todo!()
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    const EXAMPLE: &str = "1
+10
+100
+2024";
+
+    #[test]
+    fn evolution() {
+        assert_eq!(evolve_secret(123), 15887950);
+        assert_eq!(evolve_secret(15887950), 16495136);
+        assert_eq!(evolve_secret(16495136), 527345);
+    }   
+
+    #[test]
+    fn test_rounds() {
+        assert_eq!(rounds(1, 2000), 8685429);
+        assert_eq!(rounds(10, 2000), 4700978);
+    }   
+
+    #[test]
+    fn part1_example() {
+        assert_eq!(part1(EXAMPLE),37327623);
+    }
+
+    #[test]
+    fn part2_example() {
+        assert_eq!(part2(EXAMPLE), 0);
+    }
+}

src/lib.rs

@@ -12,6 +12,7 @@ pub mod day19;
 pub mod day2;
 pub mod day20;
 pub mod day21;
+pub mod day22;
 pub mod day3;
 pub mod day4;
 pub mod day5;