Finished complete day 6 aoc, was way easier than previous day

advent_of_code/2023/6/src/main.rs

@@ -0,0 +1,100 @@
+use std::iter::zip;
+
+use nom::{
+    bytes::complete::tag,
+    character::complete::{multispace0, multispace1, u64},
+    multi::separated_list1,
+    sequence::tuple,
+    IResult,
+};
+
+fn parse_input(input: &str) -> IResult<&str, Vec<(u64, u64)>> {
+    let (input, result) = tuple((
+        tag("Time:"),
+        multispace0,
+        separated_list1(multispace1, u64),
+        multispace0,
+        tag("Distance:"),
+        multispace0,
+        separated_list1(multispace1, u64),
+    ))(input)
+    .map(|(i, (_, _, times, _, _, _, distances))| (i, (times, distances)))?;
+
+    let result = zip(result.0, result.1).collect();
+
+    Ok((input, result))
+}
+
+fn record_beating_ways(time_distance_pair: (u64, u64)) -> usize {
+    (1..=time_distance_pair.0)
+        .into_iter()
+        .filter(|&time_charging| {
+            (time_distance_pair.0 - time_charging) * time_charging > time_distance_pair.1
+        })
+        .count()
+}
+
+fn solve_1(time_distance_pairs: &[(u64, u64)]) -> u64 {
+    time_distance_pairs
+        .iter()
+        .map(|&pair| record_beating_ways(pair) as u64)
+        .product()
+}
+
+fn solve_2(time_distance_pairs: &[(u64, u64)]) -> u64 {
+    let time_distance_pair = time_distance_pairs.iter().fold(
+        (0, 0),
+        |(output_time, output_distance), &(time, distance)| {
+            let time_len = (time as f64).log10().floor() as u32 + 1;
+            let distance_len = (distance as f64).log10().floor() as u32 + 1;
+
+            (
+                output_time * 10u64.pow(time_len) as u64 + time,
+                output_distance * 10u64.pow(distance_len) as u64 + distance,
+            )
+        },
+    );
+
+    record_beating_ways(time_distance_pair) as u64
+}
+
+fn main() {
+    println!("Hello, this is Patrick!");
+
+    let input_text = include_str!("../input.txt");
+
+    let (_, time_distance_pairs) = parse_input(input_text).unwrap();
+
+    println!(
+        "The product of the number of ways you could beat the record is {}",
+        solve_1(&time_distance_pairs[..])
+    );
+
+    println!(
+        "The longer race can be won in {} ways",
+        solve_2(&time_distance_pairs[..])
+    );
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1() {
+        let input_text = include_str!("../test_input.txt");
+
+        let (_, time_distance_pairs) = parse_input(input_text).unwrap();
+
+        assert_eq!(solve_1(&time_distance_pairs[..]), 288);
+    }
+
+    #[test]
+    fn test_2() {
+        let input_text = include_str!("../test_input.txt");
+
+        let (_, time_distance_pairs) = parse_input(input_text).unwrap();
+
+        assert_eq!(solve_2(&time_distance_pairs[..]), 71503);
+    }
+}