finished day 04 part 1

2023/day-04/src/bin/part1.rs

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+use color_eyre::Result;
+use day_04::part1::process;
+
+fn main() -> Result<()> {
+    let file = include_str!("../../input1.txt");
+    let result = process(file)?;
+    println!("{}", result);
+    Ok(())
+}

2023/day-04/src/bin/part2.rs

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+use color_eyre::Result;
+use day_04::part2::process;
+
+fn main() -> Result<()> {
+    let file = include_str!("../../input2.txt");
+    let result = process(file)?;
+    println!("{}", result);
+    Ok(())
+}

2023/day-04/src/lib.rs

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+pub mod part1;
+pub mod part2;

2023/day-04/src/part1.rs

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+use std::{borrow::BorrowMut, str::FromStr};
+
+#[derive(Debug, Clone)]
+#[allow(dead_code)]
+struct Card {
+    id: usize,
+    win_nums: Vec<usize>,
+    my_nums: Vec<usize>,
+    points: usize,
+}
+
+impl Card {
+    fn add_point(&mut self) {
+        if self.points == 0 {
+            self.points = 1
+        } else {
+            self.points *= 2
+        }
+    }
+}
+
+impl FromStr for Card {
+    type Err = &'static str;
+    fn from_str(s: &str) -> std::prelude::v1::Result<Self, Self::Err> {
+        let line: Vec<_> = s.split(|ch| ch == ':' || ch == '|').collect();
+
+        let id = line
+            .get(0)
+            .ok_or("Missing ID field")
+            .and_then(|field| field.split_whitespace().last().ok_or("Invalid ID format"))
+            .and_then(|id_str| id_str.parse::<usize>().map_err(|_| "Failed to parse ID"))?;
+
+        let win_nums: Result<Vec<_>, _> = line
+            .get(1)
+            .ok_or("Missing winning numbers field")
+            .and_then(|field| {
+                field
+                    .split_whitespace()
+                    .map(|num| {
+                        num.parse::<usize>()
+                            .map_err(|_| "Winning numbers should be numbers")
+                    })
+                    .collect()
+            });
+
+        let my_nums: Result<Vec<_>, _> =
+            line.get(2)
+                .ok_or("Missing 'my' numbers field")
+                .and_then(|field| {
+                    field
+                        .split_whitespace()
+                        .map(|num| {
+                            num.parse::<usize>()
+                                .map_err(|_| "'My' numbers should be numbers")
+                        })
+                        .collect()
+                });
+
+        Ok(Self {
+            id,
+            win_nums: win_nums?,
+            my_nums: my_nums?,
+            points: 0,
+        })
+    }
+}
+
+pub fn process(input: &str) -> color_eyre::Result<usize> {
+    let mut cards: Vec<Card> = input.lines().flat_map(Card::from_str).collect();
+
+    let sum = cards
+        .iter_mut()
+        .flat_map(|card| {
+            for num in card.win_nums.clone() {
+                if card.my_nums.contains(&num) {
+                    card.add_point();
+                }
+            }
+            Some(card.points)
+        })
+        .sum();
+
+    Ok(sum)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_process() -> color_eyre::Result<()> {
+        let input = "Card 1: 41 48 83 86 17 | 83 86  6 31 17  9 48 53
+Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19
+Card 3:  1 21 53 59 44 | 69 82 63 72 16 21 14  1
+Card 4: 41 92 73 84 69 | 59 84 76 51 58  5 54 83
+Card 5: 87 83 26 28 32 | 88 30 70 12 93 22 82 36
+Card 6: 31 18 13 56 72 | 74 77 10 23 35 67 36 11";
+        assert_eq!(13, process(input)?);
+        Ok(())
+    }
+}

2023/day-04/src/part2.rs

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+use color_eyre::Result;
+
+pub fn process(_input: &str) -> Result<u32> {
+    Ok(0)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_process() -> Result<()> {
+        let input = "";
+        assert_eq!(0, process(input)?);
+        Ok(())
+    }
+}