Implement with Coordinates struct

src/day_three.rs

@@ -1,14 +1,66 @@
+use std::cmp::Ordering;
 use std::collections::BTreeSet;
 use std::io;
 use std::iter::{repeat, successors};
 
-fn next(c: (i32, i32), direction: &str) -> (i32, i32) {
-    match direction {
-        "R" => (c.0 + 1, c.1),
-        "L" => (c.0 - 1, c.1),
-        "U" => (c.0, c.1 + 1),
-        "D" => (c.0, c.1 - 1),
-        _ => panic!("Wrong direction format!"),
+#[derive(Clone, Copy, Debug, Eq)]
+struct Coordinate {
+    step: usize,
+    x: i32,
+    y: i32,
+}
+
+impl PartialEq for Coordinate {
+    fn eq(&self, other: &Self) -> bool {
+        self.x == other.x && self.y == other.y
+    }
+}
+
+impl Ord for Coordinate {
+    fn cmp(&self, other: &Self) -> Ordering {
+        self.x.cmp(&other.x)
+    }
+}
+
+impl PartialOrd for Coordinate {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        self.y.partial_cmp(&other.y)
+    }
+}
+
+impl Coordinate {
+    fn new() -> Self {
+        Self {
+            step: 0,
+            x: 0,
+            y: 0,
+        }
+    }
+
+    fn next(self: &Self, direction: &str) -> Coordinate {
+        match direction {
+            "R" => Coordinate {
+                step: self.step + 1,
+                x: self.x + 1,
+                y: self.y,
+            },
+            "L" => Coordinate {
+                step: self.step + 1,
+                x: self.x - 1,
+                y: self.y,
+            },
+            "U" => Coordinate {
+                step: self.step + 1,
+                x: self.x,
+                y: self.y + 1,
+            },
+            "D" => Coordinate {
+                step: self.step + 1,
+                x: self.x,
+                y: self.y - 1,
+            },
+            _ => panic!("Wrong direction format!"),
+        }
     }
 }
 
@@ -19,7 +71,7 @@ fn direction_length(entry: String) -> (String, usize) {
     )
 }
 
-fn to_coordinates(entries: Vec<String>) -> BTreeSet<(i32, i32)> {
+fn to_coordinates(entries: Vec<String>) -> BTreeSet<Coordinate> {
     let mut wire = BTreeSet::new();
 
     let mut it = entries
@@ -29,8 +81,8 @@ fn to_coordinates(entries: Vec<String>) -> BTreeSet<(i32, i32)> {
 
     successors(
         it.next()
-            .map(|direction| (next((0, 0), direction.as_ref()))),
-        |c| it.next().map(|direction| (next(*c, direction.as_ref()))),
+            .map(|direction| (Coordinate::next(&Coordinate::new(), direction.as_ref()))),
+        |c| it.next().map(|direction| (c.next(direction.as_ref()))),
     )
     .for_each(|c| {
         wire.insert(c);
@@ -39,26 +91,33 @@ fn to_coordinates(entries: Vec<String>) -> BTreeSet<(i32, i32)> {
     wire
 }
 
-fn distance(position: (i32, i32)) -> i32 {
-    position.0.abs() + position.1.abs()
-}
-
 fn closest(input: String) -> Option<i32> {
-    let entries: Vec<BTreeSet<(i32, i32)>> = input
+    let entries: Vec<BTreeSet<Coordinate>> = input
         .trim()
         .split("\n")
         .map(|line| line.split(",").map(String::from).collect())
         .map(to_coordinates)
         .collect();
 
+    println!(
+        "{:?}",
+        entries[0]
+            .intersection(&entries[1])
+            .cloned()
+            .map(|c| c.x.abs() + c.y.abs())
+            .collect::<Vec<i32>>()
+    );
+
     entries[0]
         .intersection(&entries[1])
         .cloned()
-        .map(distance)
+        .map(|c| c.x.abs() + c.y.abs())
         .min()
 }
 
-fn first(input: String) -> Option<i32> {}
+fn best(input: String) -> Option<i32> {
+    None
+}
 
 pub fn main() -> io::Result<()> {
     let closest = closest(std::include_str!("../day3-input.txt").to_owned());
@@ -69,17 +128,37 @@ pub fn main() -> io::Result<()> {
 
 #[test]
 fn test_coordinates_for_entry() {
-    let mut expected: BTreeSet<(i32, i32)> = BTreeSet::new();
+    let mut expected: BTreeSet<Coordinate> = BTreeSet::new();
     for i in 1..11 {
-        expected.insert((i, 0));
+        expected.insert(Coordinate {
+            step: i,
+            x: i as i32,
+            y: 0,
+        });
     }
     assert_eq!(to_coordinates(vec!["R10".to_owned()]), expected);
 
     expected = BTreeSet::new();
-    expected.insert((1, 0));
-    expected.insert((2, 0));
-    expected.insert((2, 1));
-    expected.insert((2, 2));
+    expected.insert(Coordinate {
+        step: 1,
+        x: 1,
+        y: 0,
+    });
+    expected.insert(Coordinate {
+        step: 2,
+        x: 2,
+        y: 0,
+    });
+    expected.insert(Coordinate {
+        step: 3,
+        x: 1,
+        y: 1,
+    });
+    expected.insert(Coordinate {
+        step: 4,
+        x: 2,
+        y: 2,
+    });
     let input = "R2,U2".to_owned().split(",").map(String::from).collect();
     assert_eq!(to_coordinates(input), expected);
 }