feat(09/2025): solve first part

Author: manhunto

readme.md

@@ -19,6 +19,7 @@
 | [Day 6: Trash Compactor](src/solutions/year2025/day06.rs)     |   ⭐⭐   |            0.117 |            2.577 |
 | [Day 7: Laboratories](src/solutions/year2025/day07.rs)        |   ⭐⭐   |            6.711 |            5.789 |
 | [Day 8: Playground](src/solutions/year2025/day08.rs)          |   ⭐⭐   |           46.993 |           44.599 |
+| [Day 9: Movie Theater](src/solutions/year2025/day09.rs)       |   ⭐    |            0.387 |                - |
 
 # 2024
 

src/solutions/year2025/day09.rs

@@ -1,26 +1,48 @@
 use crate::solutions::Solution;
+use crate::utils::point::Point;
+use crate::utils::surface_range::SurfaceRange;
+use itertools::Itertools;
 
 pub struct Day09;
 
 impl Solution for Day09 {
-    fn part_one(&self, _input: &str) -> String {
-        String::from("0")
+    fn part_one(&self, input: &str) -> String {
+        self.parse(input)
+            .into_iter()
+            .tuple_combinations()
+            .map(|(a, b)| SurfaceRange::from((a, b)).area())
+            .max()
+            .unwrap()
+            .to_string()
     }
 
     fn part_two(&self, _input: &str) -> String {
         String::from("0")
     }
 }
 
+impl Day09 {
+    fn parse(&self, input: &str) -> Vec<Point> {
+        input.lines().map(|line| line.parse().unwrap()).collect()
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::solutions::year2025::day09::Day09;
     use crate::solutions::Solution;
 
-    const EXAMPLE: &str = r#""#;
+    const EXAMPLE: &str = r#"7,1
+11,1
+11,7
+9,7
+9,5
+2,5
+2,3
+7,3"#;
 
     #[test]
     fn part_one_example_test() {
-        assert_eq!("0", Day09.part_one(EXAMPLE));
+        assert_eq!("50", Day09.part_one(EXAMPLE));
     }
 }

src/utils/range.rs

@@ -17,6 +17,10 @@ impl Range {
         Ok(Self { start, end })
     }
 
+    pub fn from_unordered(a: isize, b: isize) -> Self {
+        Self::new(a.min(b), a.max(b)).unwrap()
+    }
+
     pub fn with_length(start: isize, len: isize) -> Result<Self, String> {
         Self::new(start, start + len - 1)
     }

src/utils/surface_range.rs

@@ -16,8 +16,8 @@ impl SurfaceRange {
 
     pub fn from_points(start_x: isize, end_x: isize, start_y: isize, end_y: isize) -> Self {
         Self::new(
-            Range::new(start_x, end_x).unwrap(),
-            Range::new(start_y, end_y).unwrap(),
+            Range::from_unordered(start_x, end_x),
+            Range::from_unordered(start_y, end_y),
         )
     }
 
@@ -87,6 +87,12 @@ impl SurfaceRange {
     }
 }
 
+impl From<(Point, Point)> for SurfaceRange {
+    fn from((a, b): (Point, Point)) -> Self {
+        Self::from_points(a.x, b.x, a.y, b.y)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::utils::surface_range::SurfaceRange;