[TASK] Solved Day 1 (but not very pretty)

src/util.rs

@@ -54,6 +54,7 @@ impl<T: Clone + Sized> Grid<T> {
         &self.data[idx]
     }
 
+    #[allow(dead_code)]
     pub fn set(&mut self, x: &usize, y: &usize, v: T) {
         let idx = self.idx(x, y);
         self.data[idx] = v;