12th day (part_one)

Author: majcn

data/examples/12.txt

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+RRRRIICCFF
+RRRRIICCCF
+VVRRRCCFFF
+VVRCCCJFFF
+VVVVCJJCFE
+VVIVCCJJEE
+VVIIICJJEE
+MIIIIIJJEE
+MIIISIJEEE
+MMMISSJEEE

src/bin/12.rs

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+advent_of_code::solution!(12);
+
+use advent_of_code::maneatingape::grid::*;
+use advent_of_code::maneatingape::point::*;
+
+fn parse_data(input: &str) -> Grid<u8> {
+    Grid::parse(input)
+}
+
+fn find_data_with_flood(grid: &Grid<u8>) -> Vec<(usize, usize)> {
+    let mut visited = grid.same_size_with(false);
+
+    let mut result = vec![];
+
+    for y in 0..grid.height {
+        for x in 0..grid.width {
+            let start_location = Point::new(x, y);
+            if visited[start_location] {
+                continue;
+            }
+
+            let plot = grid[start_location];
+
+            let mut area = 0;
+            let mut perimeter = 0;
+
+            let mut queue = vec![start_location];
+            while let Some(position) = queue.pop() {
+                if visited[position] {
+                    continue;
+                }
+                visited[position] = true;
+
+                area += 1;
+                perimeter += 4;
+
+                for new_position in ORTHOGONAL.map(|o| position + o) {
+                    if grid.contains(new_position) && grid[new_position] == plot {
+                        queue.push(new_position);
+                        perimeter -= 1;
+                    }
+                }
+            }
+
+            result.push((area, perimeter));
+        }
+    }
+
+    result
+}
+
+pub fn part_one(input: &str) -> Option<u32> {
+    let grid = parse_data(input);
+
+    let result = find_data_with_flood(&grid)
+        .into_iter()
+        .map(|(area, perimeter)| (area * perimeter) as u32)
+        .sum();
+
+    Some(result)
+}
+
+pub fn part_two(_input: &str) -> Option<u32> {
+    None
+}
+
+#[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(1930));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, None);
+    }
+}