Completed day one

day_01/src/lib.rs

@@ -0,0 +1,50 @@
+use std::iter::zip;
+
+const WORD_LIST: [&str; 9] = ["one", "two", "three", "four", "five", "six", "seven", "eight", "nine"];
+const DIGIT_LIST: [&str; 9] = ["one1one", "two2two", "three3three", "four4four", "five5five", "six6six", "seven7seven", "eight8eight", "nine9nine"];
+
+fn find_first_digit(line: &str) -> u32 {
+    match line.chars().find(|character| { character.is_digit(10) }) {
+        Some(x) => x.to_digit(10).unwrap(),
+        None => 0,
+    }
+}
+
+fn find_last_digit(line: &str) -> u32 {
+    match line.chars().rev().find(|character| { character.is_digit(10) }) {
+        Some(x) => x.to_digit(10).unwrap(),
+        None => 0,
+    }
+}
+
+fn replace_with_digits(input: &str) -> String {
+    let mut output = input.to_string();
+    for (word, digit) in zip(WORD_LIST, DIGIT_LIST) {
+        output = output.replace(word, digit).to_string();
+    }
+    output
+}
+
+pub fn part1(input: &str) -> String {
+    let calibration_lines = input
+        .split("\n")
+        .map(|line| {
+            let first = find_first_digit(line);
+            let last = find_last_digit(line);
+            format!("{}{}", first, last).parse::<u32>().unwrap()
+        })
+        .collect::<Vec<_>>();
+    format!("{}", calibration_lines.into_iter().sum::<u32>())
+}
+
+pub fn part2(input: &str) -> String {
+    let parsed_inputs = &replace_with_digits(input);
+    dbg!(parsed_inputs);
+    part1(parsed_inputs)
+}
+
+pub mod prelude {
+    pub use super::part1;
+    pub use super::part2;
+}
+

day_01/src/main.rs

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+use day_01::prelude::*;
+
+fn main() {
+    let input = include_str!("../input.txt");
+    println!("{}", part1(input));
+    println!("{}", part2(input));
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part1() {
+        let test_input = "1abc2
+pqr3stu8vwx
+a1b2c3d4e5f
+treb7uchet";
+        assert_eq!(part1(test_input), "142".to_string());
+    }
+
+    #[test]
+    fn test_part2() {
+        let test_input = "two1nine
+eightwothree
+abcone2threexyz
+xtwone3four
+4nineeightseven2
+zoneight234
+7pqrstsixteen";
+        assert_eq!(part2(test_input), "281".to_string());
+    }
+
+}