Day 7 down

Author: BakerNet

README.md

@@ -10,7 +10,7 @@ Solutions for [Advent of Code](https://adventofcode.com/) in [Rust](https://www.
 
 | Year | Completed |
 | :---: | :---: |
-| [2025](aoc2025) | 12/24 |
+| [2025](aoc2025) | 14/24 |
 | [2024](aoc2024) | 50/50 |
 | [2023](aoc2023) | 50/50 |
 | [2015](aoc2015) | 12/50 |

aoc2025/README.md

@@ -12,7 +12,7 @@ Solutions for [Advent of Code](https://adventofcode.com/) in [Rust](https://www.
 | [Day 4](https://adventofcode.com/2025/day/4) | [code](src/bin/04.rs) | ⭐ | ⭐ |
 | [Day 5](https://adventofcode.com/2025/day/5) | [code](src/bin/05.rs) | ⭐ | ⭐ |
 | [Day 6](https://adventofcode.com/2025/day/6) | [code](src/bin/06.rs) | ⭐ | ⭐ |
-| [Day 7](https://adventofcode.com/2025/day/7) | [code](src/bin/07.rs) | _ | _ |
+| [Day 7](https://adventofcode.com/2025/day/7) | [code](src/bin/07.rs) | ⭐ | ⭐ |
 | [Day 8](https://adventofcode.com/2025/day/8) | [code](src/bin/08.rs) | _ | _ |
 | [Day 9](https://adventofcode.com/2025/day/9) | [code](src/bin/09.rs) | _ | _ |
 | [Day 10](https://adventofcode.com/2025/day/10) | [code](src/bin/10.rs) | _ | _ |

aoc2025/data/examples/07.txt

@@ -0,0 +1,16 @@
+.......S.......
+...............
+.......^.......
+...............
+......^.^......
+...............
+.....^.^.^.....
+...............
+....^.^...^....
+...............
+...^.^...^.^...
+...............
+..^...^.....^..
+...............
+.^.^.^.^.^...^.
+...............

aoc2025/src/bin/07.rs

@@ -0,0 +1,65 @@
+use aoc_utils::*;
+
+advent_of_code::solution!(7);
+
+pub fn part_one(input: &str) -> Option<u64> {
+    let mut map = input.c_map();
+    let mut splits = 0;
+    for r in 1..map.len() {
+        for c in 0..map[r].len() {
+            let prev = map[r - 1][c];
+            let curr = map[r][c];
+            match (prev, curr) {
+                ('S' | '|', '.') => map[r][c] = '|',
+                ('S' | '|', '^') => {
+                    splits += 1;
+                    map[r][c - 1] = '|';
+                    map[r][c + 1] = '|';
+                }
+                _ => (),
+            }
+        }
+    }
+    Some(splits)
+}
+
+pub fn part_two(input: &str) -> Option<u64> {
+    let map = input.c_map();
+    let mut map_counts = vec![vec![0; map[0].len()]; map.len()];
+    for r in 0..map.len() {
+        for c in 0..map[r].len() {
+            let prev = map_counts[if r > 0 { r - 1 } else { 0 }][c];
+            let curr = map[r][c];
+            match (prev, curr) {
+                (_, 'S') => map_counts[r][c] = 1,
+                (x, '.') if x > 0 => {
+                    map_counts[r][c] += map_counts[r - 1][c];
+                }
+                (x, '^') if x > 0 => {
+                    map_counts[r][c - 1] += map_counts[r - 1][c];
+                    map_counts[r][c + 1] += map_counts[r - 1][c];
+                }
+                _ => (),
+            }
+        }
+    }
+    let timelines = map_counts[map_counts.len() - 1].iter().sum();
+    Some(timelines)
+}
+
+#[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(21));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(40));
+    }
+}