2024: move to single Rust crate

1 files changed, 45 insertions, 0 deletions

diff --git a/2024_rust/src/day1.rs b/2024_rust/src/day1.rs
new file mode 100644
index 0000000..0b6c13d
--- /dev/null
+++ b/2024_rust/src/day1.rs
@@ -0,0 +1,45 @@
+pub fn p1(input: &str) -> String {
+    let mut left: Vec<u32> = vec![];
+    let mut right: Vec<u32> = vec![];
+    for line in input.lines() {
+        let mut fields = line.split_whitespace();
+        let e = "Wrong file format";
+        left.push(fields.next().expect(e).parse().expect(e));
+        right.push(fields.next().expect(e).parse().expect(e));
+    }
+    left.sort_unstable();
+    right.sort_unstable();
+
+    let mut distance: u32 = 0;
+    for i in 0..left.len() {
+        let l = left[i];
+        let r = right[i];
+        distance += if l >= r { l - r } else { r - l };
+    }
+
+    distance.to_string()
+}
+
+use std::collections::HashMap;
+
+pub fn p2(input: &str) -> String {
+    let mut left: Vec<u32> = vec![];
+    let mut right: HashMap<u32, u32> = HashMap::new();
+    for line in input.lines() {
+        let mut fields = line.split_whitespace();
+        let e = "Wrong file format";
+        left.push(fields.next().expect(e).parse().expect(e));
+        let r: u32 = fields.next().expect(e).parse().expect(e);
+        match right.get(&r) {
+            None => right.insert(r, 1),
+            Some(v) => right.insert(r, v + 1),
+        };
+    }
+
+    let mut distance: u32 = 0;
+    for l in left {
+        distance += l * right.get(&l).unwrap_or(&0);
+    }
+
+    distance.to_string()
+}