Merge branch 'day-01'

day-01/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "day-01"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+color-eyre = { workspace = true }

day-01/src/bin/part1.rs

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+use color_eyre::Result;
+use day_01::part1::process;
+
+fn main() -> Result<()> {
+    let file = include_str!("../../input1.txt");
+    let result = process(file)?;
+    println!("{}", result);
+    Ok(())
+}

day-01/src/bin/part2.rs

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+use color_eyre::Result;
+use day_01::part2::process;
+
+fn main() -> Result<()> {
+    let file = include_str!("../../input2.txt");
+    let result = process(file)?;
+    println!("{}", result);
+    Ok(())
+}

day-01/src/lib.rs

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+pub mod part1;
+pub mod part2;

day-01/src/part1.rs

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+use color_eyre::Result;
+
+pub fn process(input: &str) -> Result<u32> {
+    let sum: u32 = input
+        .lines()
+        .flat_map(|line| {
+            let digits: Vec<u32> = line.chars().filter_map(|char| char.to_digit(10)).collect();
+            match (digits.first(), digits.last()) {
+                (Some(first), Some(last)) => Some(first * 10 + last),
+                _ => None,
+            }
+        })
+        .sum();
+
+    Ok(sum)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn test_process() -> Result<()> {
+        let input = "1abc2
+pqr3stu8vwx
+a1b2c3d4e5f
+treb7uchet";
+        assert_eq!(142, process(input)?);
+        Ok(())
+    }
+}

day-01/src/part2.rs

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+use color_eyre::Result;
+
+pub fn process(input: &str) -> Result<u32> {
+    let sum: u32 = input.lines().map(process_line).sum();
+
+    Ok(sum)
+}
+
+fn process_line(line: &str) -> u32 {
+    let mut it = (0..line.len()).filter_map(|index| {
+        let reduced_line = &line[index..];
+        let result = if reduced_line.starts_with("one") {
+            Some(1)
+        } else if reduced_line.starts_with("two") {
+            Some(2)
+        } else if reduced_line.starts_with("three") {
+            Some(3)
+        } else if reduced_line.starts_with("four") {
+            Some(4)
+        } else if reduced_line.starts_with("five") {
+            Some(5)
+        } else if reduced_line.starts_with("six") {
+            Some(6)
+        } else if reduced_line.starts_with("seven") {
+            Some(7)
+        } else if reduced_line.starts_with("eight") {
+            Some(8)
+        } else if reduced_line.starts_with("nine") {
+            Some(9)
+        } else {
+            reduced_line.chars().next().unwrap().to_digit(10)
+        };
+        result
+    });
+
+    let first = it.next().expect("Should be a number");
+
+    match it.last() {
+        Some(num) => first * 10 + num,
+        None => first * 10 + first,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn test_process() -> Result<()> {
+        let input = "two1nine
+eightwothree
+abcone2threexyz
+xtwone3four
+4nineeightseven2
+zoneight234
+7pqrstsixteen";
+        assert_eq!(281, process(input)?);
+        Ok(())
+    }
+}