feat: solve day 6

data/examples/06.txt

@@ -0,0 +1,4 @@
+123 328  51 64
+ 45 64  387 23
+  6 98  215 314
+*   +   *   +  

src/bin/06.rs

@@ -0,0 +1,102 @@
+use itertools::Itertools;
+
+advent_of_code::solution!(6);
+
+pub fn part_one(input: &str) -> Option<u64> {
+    let number_rows = input
+        .lines()
+        .filter(|line| {
+            !line.is_empty() && line.chars().find(|c| *c != ' ').unwrap_or(' ').is_numeric()
+        })
+        .map(|line| {
+            line.split(" ")
+                .filter(|s| !s.is_empty())
+                .map(|s| s.parse().unwrap_or(0))
+                .collect::<Vec<u64>>()
+        })
+        .collect::<Vec<Vec<u64>>>();
+    let operators = input
+        .lines()
+        .last()
+        .unwrap()
+        .split(" ")
+        .filter(|s| !s.is_empty());
+    operators
+        .enumerate()
+        .map(|(i, operator)| match operator {
+            "+" => number_rows.iter().map(|row| row[i]).sum(),
+            "*" => number_rows.iter().map(|row| row[i]).product(),
+            _ => 0,
+        })
+        .sum1()
+}
+
+pub fn part_two(input: &str) -> Option<u64> {
+    let operators = input
+        .lines()
+        .last()
+        .unwrap()
+        .split(" ")
+        .filter(|s| !s.is_empty());
+    let number_rows = input
+        .lines()
+        .filter(|line| {
+            !line.is_empty() && line.chars().find(|c| *c != ' ').unwrap_or(' ').is_numeric()
+        })
+        .map(|line| line.chars().collect())
+        .collect::<Vec<Vec<char>>>();
+
+    let width = input.lines().map(|line| line.len()).max().unwrap_or(0);
+    let height = input
+        .lines()
+        .filter(|line| {
+            !line.is_empty() && line.chars().find(|c| *c != ' ').unwrap_or(' ').is_numeric()
+        })
+        .count();
+    let mut chunks = vec![];
+    let mut curr_chunk = vec![];
+    for col in 0..width {
+        let mut chars = vec![];
+        for row in 0..height {
+            if col >= number_rows[row].len() {
+                chars.push(' ');
+            } else {
+                chars.push(number_rows[row][col]);
+            }
+        }
+        let num_str = chars.iter().join("");
+        if num_str.trim().is_empty() {
+            chunks.push(curr_chunk);
+            curr_chunk = vec![];
+        } else {
+            curr_chunk.push(num_str.trim().parse().unwrap());
+        }
+    }
+    chunks.push(curr_chunk);
+
+    operators
+        .enumerate()
+        .map(|(i, operator)| match operator {
+            "+" => chunks[i].iter().sum(),
+            "*" => chunks[i].iter().product(),
+            _ => 0,
+        })
+        .sum1()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let result = part_one(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(4277556));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(3263827));
+    }
+}