data/examples/09.txt

@@ -1,3 +0,0 @@
-0 3 6 9 12 15
-1 3 6 10 15 21
-10 13 16 21 30 45

src/bin/09.rs

@@ -1,87 +0,0 @@
-use std::collections::VecDeque;
-
-fn find_history(v: VecDeque<i32>) -> VecDeque<VecDeque<i32>> {
-    let mut s = VecDeque::new();
-    s.push_back(v);
-
-    loop {
-        let mut all_zeros = true;
-
-        let last = s.back().unwrap();
-        let mut new = VecDeque::new();
-        for i in 0..(last.len() - 1) {
-            let diff = last[i + 1] - last[i];
-            if diff != 0 {
-                all_zeros = false;
-            }
-
-            new.push_back(diff);
-        }
-        s.push_back(new);
-
-        if all_zeros {
-            break;
-        }
-    }
-
-    s
-}
-
-fn extrapolate_forward(v: VecDeque<i32>) -> i32 {
-    let mut s = find_history(v);
-
-    for i in (1..s.len()).rev() {
-        let adder = *s[i].back().unwrap();
-        let last = *s[i - 1].back().unwrap();
-        s[i - 1].push_back(last + adder);
-    }
-
-    *s[0].back().unwrap()
-}
-
-fn extrapolate_back(v: VecDeque<i32>) -> i32 {
-    let mut s = find_history(v);
-
-    for i in (1..s.len()).rev() {
-        let adder = *s[i].front().unwrap();
-        let first = *s[i - 1].front().unwrap();
-        s[i - 1].push_front(first - adder);
-    }
-
-    *s[0].front().unwrap()
-}
-
-pub fn part_one(input: &str) -> Option<i32> {
-    Some(
-        input
-            .lines()
-            .map(|x| x.split(' ').filter_map(|y| y.parse().ok()).collect())
-            .map(extrapolate_forward)
-            .sum(),
-    )
-}
-
-pub fn part_two(input: &str) -> Option<i32> {
-    Some(
-        input
-            .lines()
-            .map(|x| x.split(' ').filter_map(|y| y.parse().ok()).collect())
-            .map(extrapolate_back)
-            .sum(),
-    )
-}
-
-aoc::solution!(9);
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    #[test]
-    fn test_part_one() {
-        assert_eq!(part_one(&aoc::template::read_file("examples", 9)), None);
-    }
-    #[test]
-    fn test_part_two() {
-        assert_eq!(part_two(&aoc::template::read_file("examples", 9)), None);
-    }
-}

src/lib.rs

@@ -1,10 +1,10 @@
 #![feature(pattern)]
 
+use std::mem::swap;
+
 pub mod parsers;
 pub mod template;
 
-use std::mem::swap;
-
 pub fn lcm(first: usize, second: usize) -> usize {
     first * second / gcd(first, second)
 }