fix: check the rust codes and fix them (#653)

* fix: check the rust codes and fix it

* Update binary_tree_bfs.rs

---------

Co-authored-by: Yudong Jin <krahets@163.com>

codes/rust/chapter_hashing/array_hash_map.rs

@@ -43,6 +43,7 @@ impl ArrayHashMap {
     /* 删除操作 */
     pub fn remove(&mut self, key: i32) {
         let index = self.hash_func(key);
+        // 置为 None ，代表删除
         self.buckets[index] = None;
     }