Solve 2023 day 03 part 1

src/lib/solutions/year_2023/day_03.rs

@@ -3,13 +3,102 @@ use crate::utils::solution::Solution;
 pub struct Day03 {}
 
 impl Solution for Day03 {
-    fn part_one(&self, _input: &str) -> Option<String> {
-        None
+    fn part_one(&self, input: &str) -> Option<String> {
+        Some(sum_part_adjacent_numbers(&char_grid(input)).to_string())
     }
 
     fn part_two(&self, _input: &str) -> Option<String> {
         None
     }
 }
 
+fn char_grid(s: &str) -> Vec<Vec<char>> {
+    s.lines().map(|line| line.chars().collect()).collect()
+}
+
+fn sum_part_adjacent_numbers(char_grid: &Vec<Vec<char>>) -> i32 {
+    let num_cols = match char_grid.first() {
+        Some(row) => row.len(),
+        None => 0,
+    };
+
+    let mut total = 0;
+
+    for row_idx in 0..char_grid.len() {
+        let row = char_grid.get(row_idx).unwrap();
+
+        let mut col_idx = 0;
+
+        'columns: while (0..num_cols).contains(&col_idx) {
+            if !row[col_idx].is_numeric() {
+                col_idx += 1;
+                continue;
+            }
+
+            let mut word_len = 0;
+            while col_idx + word_len < row.len() && row[col_idx + word_len].is_numeric() {
+                word_len += 1;
+            }
+
+            let lower_row = ((row_idx as i32) - 1).max(0) as usize;
+            let upper_row = (row_idx + 1).min(char_grid.len() - 1);
+
+            let lower_col = ((col_idx as i32) - 1).max(0) as usize;
+            let upper_col = (col_idx + word_len).min(num_cols - 1);
+
+            for adjacent_row in lower_row..=upper_row {
+                for adjacent_col in lower_col..=upper_col {
+                    if adjacent_row == row_idx
+                        && (col_idx..(col_idx + word_len)).contains(&adjacent_col)
+                    {
+                        continue;
+                    }
+
+                    let adjacent_char = char_grid[adjacent_row][adjacent_col];
+                    let is_symbol = !adjacent_char.is_numeric() && adjacent_char != '.';
+
+                    if !is_symbol {
+                        continue;
+                    }
+
+                    let number = char_grid[row_idx][col_idx..(col_idx + word_len)]
+                        .iter()
+                        .collect::<String>();
+
+                    println!("{number}");
+
+                    total += number.parse::<i32>().expect("expected numeric string");
+                    col_idx += word_len;
+                    continue 'columns;
+                }
+            }
+
+            col_idx += word_len + 1;
+        }
+    }
+
+    total
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn example() {
+        const INPUT: &str = "467..114..
+...*......
+..35..633.
+......#...
+617*......
+.....+.58.
+..592.....
+......755.
+...$.*....
+.664.598..
+";
+        assert_eq!(sum_part_adjacent_numbers(&char_grid(INPUT)), 4361);
+    }
+}
+
 crate::verify!(Day03, crate::my_input!("2023", "Day03"), "", "");

utils/get_input.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 # USAGE: ADVENT_TOKEN=<sesion> get_input.sh year day
 
-echo $ADVENT_TOKEN
+#echo $ADVENT_TOKEN
 
 currentYear=$(date +%Y)
 year=$1