solution: day 14

src/days.rs

@@ -11,7 +11,7 @@ pub mod d10;
 pub mod d11;
 pub mod d12;
 pub mod d13;
-// pub mod d14;
+pub mod d14;
 // pub mod d15;
 // pub mod d16;
 // pub mod d17;

src/days/d14.rs

@@ -0,0 +1,128 @@
+use crate::prelude::*;
+
+pub type I = &'static str;
+pub type O = usize;
+
+fn _parse (data: &str) -> I {
+    Default::default()
+}
+
+fn _solve (data: &I) -> O {
+    Default::default()
+}
+
+fn _silver (data: &I) -> O {
+    let mut candidates: M<char, Vec<usize>> = M::new();
+    let mut done: Vec<usize> = vec![];
+
+    for i in 0.. {
+        let s = format!("{data}{i}");
+        let hash = md5::compute(s);
+        let repr = format!("{:x}", hash);
+
+        let three = repr.chars().tuple_windows().find(|&(a, b, c)| a == b && b == c);
+
+        if let Some((c, _, _)) = three {
+            if !candidates.is_empty() {
+                let five = repr.chars().tuple_windows().find(|&(a, b, c, d, e)| a == b && a == c && a == d && a == e);
+                if let Some((c, _, _, _, _)) = five {
+                    if let Some(candidates) = candidates.get_mut(&c) {
+                        let pos = candidates.iter().position(|pos| pos + 1000 > i);
+                        if let Some(pos) = pos {
+                            let drained = candidates.drain(pos..).collect_vec();
+                            // println!("{} at: {:?} added to vec: {}", c, drained, repr);
+
+                            done.extend(drained);
+                            candidates.clear();
+                            if done.len() >= 100 { // extra
+                                done.sort();
+                                return done[63];
+                            }
+                        }
+                    }
+
+                }
+            }
+            candidates.entry(c).or_default().push(i);
+        }
+    }
+    // 15189: too high
+    0
+}
+
+fn _gold (data: &I) -> O {
+    let mut candidates: M<char, Vec<usize>> = M::new();
+    let mut done: Vec<usize> = vec![];
+
+    for i in 0.. {
+        let s = format!("{data}{i}");
+        let mut hash = md5::compute(s);
+        let mut repr = format!("{:x}", hash);
+
+        for _ in 0..2016 {
+            hash = md5::compute(repr);
+            repr = format!("{:x}", hash);
+        }
+
+        let three = repr.chars().tuple_windows().find(|&(a, b, c)| a == b && b == c);
+
+        if let Some((c, _, _)) = three {
+            if !candidates.is_empty() {
+                let five = repr.chars().tuple_windows().find(|&(a, b, c, d, e)| a == b && a == c && a == d && a == e);
+                if let Some((c, _, _, _, _)) = five {
+                    if let Some(candidates) = candidates.get_mut(&c) {
+                        let pos = candidates.iter().position(|pos| pos + 1000 > i);
+                        if let Some(pos) = pos {
+                            let drained = candidates.drain(pos..).collect_vec();
+                            // println!("{} at: {:?} added to vec: {}", c, drained, repr);
+
+                            done.extend(drained);
+                            candidates.clear();
+                            if done.len() >= 100 { // extra
+                                done.sort();
+                                return done[63];
+                            }
+                        }
+                    }
+
+                }
+            }
+            candidates.entry(c).or_default().push(i);
+        }
+    }
+    // 15189: too high
+    0
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    fn read () -> I {
+        "qzyelonm"
+    }
+
+    #[test]
+    fn sample () {
+        let data = "";
+        let data = _parse(data);
+
+        assert_eq!(1, 1)
+    }
+
+    #[test]
+    fn silver () {
+        let data = read();
+        let ans = _silver(&data);
+
+        assert_eq!(ans, 15168)
+    }
+
+    #[test]
+    fn gold () {
+        let data = read();
+        let ans = _gold(&data);
+
+        assert_eq!(ans, 20864)
+    }
+}