2017 day 4

Author: ictrobot

crates/year2017/src/day04.rs

@@ -0,0 +1,59 @@
+use std::collections::HashSet;
+use utils::prelude::*;
+
+/// Checking passphrase validity.
+#[derive(Clone, Debug)]
+pub struct Day04<'a> {
+    input: &'a str,
+}
+
+impl<'a> Day04<'a> {
+    pub fn new(input: &'a str, _: InputType) -> Result<Self, InputError> {
+        if let Some(w) = input.find(|c: char| !c.is_ascii_lowercase() && !c.is_ascii_whitespace()) {
+            Err(InputError::new(input, w, "expected lowercase letters"))
+        } else {
+            Ok(Self { input })
+        }
+    }
+
+    #[must_use]
+    pub fn part1(&self) -> usize {
+        let mut seen = HashSet::new();
+        self.input
+            .lines()
+            .filter(|line| {
+                seen.clear();
+                line.split_ascii_whitespace().all(|word| seen.insert(word))
+            })
+            .count()
+    }
+
+    #[must_use]
+    pub fn part2(&self) -> usize {
+        let mut seen = HashSet::new();
+        self.input
+            .lines()
+            .filter(|line| {
+                seen.clear();
+                line.split_ascii_whitespace().all(|word| {
+                    let mut letters = [0u8; 26];
+                    for b in word.bytes() {
+                        letters[b as usize - b'a' as usize] += 1;
+                    }
+                    seen.insert(letters)
+                })
+            })
+            .count()
+    }
+}
+
+examples!(Day04<'_> -> (usize, usize) [
+    {input: "aa bb cc dd ee", part1: 1},
+    {input: "aa bb cc dd aa", part1: 0},
+    {input: "aa bb cc dd aaa", part1: 1},
+    {input: "abcde fghij", part2: 1},
+    {input: "abcde xyz ecdab", part2: 0},
+    {input: "a ab abc abd abf abj", part2: 1},
+    {input: "iiii oiii ooii oooi oooo", part2: 1},
+    {input: "oiii ioii iioi iiio", part2: 0},
+]);

crates/year2017/src/lib.rs

@@ -5,4 +5,5 @@ utils::year!(2017 => year2017, ${
     1 => day01::Day01<'_>,
     2 => day02::Day02,
     3 => day03::Day03,
+    4 => day04::Day04<'_>,
 });