add 01, 02

01/Cargo.lock

@@ -0,0 +1,14 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "aoc"
+version = "0.1.0"
+
+[[package]]
+name = "aoc2024-01"
+version = "0.1.0"
+dependencies = [
+ "aoc",
+]

01/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "aoc2024-01"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+aoc = {version = "*", path = "../lib/aoc"}

01/example.txt

@@ -0,0 +1,7 @@
+two1nine
+eightwothree
+abcone2threexyz
+xtwone3four
+4nineeightseven2
+zoneight234
+7pqrstsixteen

01/src/main.rs

@@ -0,0 +1,117 @@
+use aoc::read_file;
+
+const NUMBERS_AS_DIGITS: [&str; 10] = [
+    "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine",
+];
+
+enum Direction {
+    Forward,
+    Reverse,
+}
+
+fn main() {
+    let content = read_file("a.txt");
+
+    part_a(&content);
+    part_b(&content);
+}
+
+fn part_a(content: &[String]) {
+    let mut sum = 0;
+    let mut line_value;
+
+    for line in content {
+        line_value = 0;
+
+        'inner: for ch in line.chars() {
+            if ch.is_ascii_digit() {
+                line_value += ch.to_digit(10).unwrap() * 10;
+                break 'inner;
+            }
+        }
+        'inner: for ch in line.chars().rev() {
+            if ch.is_ascii_digit() {
+                line_value += ch.to_digit(10).unwrap();
+                break 'inner;
+            }
+        }
+        sum += line_value;
+    }
+    println!("{sum}");
+}
+
+fn part_b(content: &[String]) {
+    let mut sum = 0;
+    let mut line_value;
+
+    for line in content {
+        line_value = 0;
+        let chars: Vec<_> = line.chars().collect();
+
+        'inner: for i in 0..chars.len() {
+            if chars[i].is_ascii_digit() {
+                line_value = chars[i].to_digit(10).unwrap();
+                break 'inner;
+            } else if let Some(digit) = contains_digit_as_string(&chars, i, Direction::Forward) {
+                line_value = digit;
+                break 'inner;
+            }
+        }
+
+        line_value *= 10;
+
+        'inner: for i in (0..chars.len()).rev() {
+            if chars[i].is_ascii_digit() {
+                line_value += chars[i].to_digit(10).unwrap();
+                break 'inner;
+            } else if let Some(digit) = contains_digit_as_string(&chars, i, Direction::Reverse) {
+                line_value += digit;
+                break 'inner;
+            }
+        }
+
+        sum += line_value;
+    }
+
+    println!("{sum}");
+}
+
+fn contains_digit_as_string(chars: &[char], start: usize, direction: Direction) -> Option<u32> {
+    match direction {
+        Direction::Forward => {
+            for possible_len in [3, 4, 5] {
+                let end = start + possible_len;
+                if end >= chars.len() {
+                    return None;
+                }
+
+                let s: String = chars.get(start..end).unwrap().iter().collect();
+
+                for (i, number) in NUMBERS_AS_DIGITS.iter().enumerate() {
+                    if *number == s {
+                        return Some(i as u32);
+                    }
+                }
+            }
+            None
+        }
+        Direction::Reverse => {
+            let end = start + 1;
+            for possible_len in [3, 4, 5] {
+                let (start, overflow) = end.overflowing_sub(possible_len);
+                if overflow {
+                    return None;
+                }
+
+                let s: String = chars.get(start..end).unwrap().iter().collect();
+
+                for (i, number) in NUMBERS_AS_DIGITS.iter().enumerate() {
+                    if *number == s {
+                        return Some(i as u32);
+                    }
+                }
+            }
+            None
+        }
+    }
+}