nicer with reverse

src/day_1.rs

@@ -24,9 +24,7 @@ pub fn part_2(input: &String) -> u64 {
     }).collect();
 
     elf_calorie_counts.sort_unstable();
+    elf_calorie_counts.reverse();
 
-    let start = elf_calorie_counts.len() - 3;
-    let top_3 = elf_calorie_counts.drain(start..);
-
-    top_3.sum()
+    elf_calorie_counts.iter().take(3).sum()
 }