diff --git a/problems/0106.从中序与后序遍历序列构造二叉树.md b/problems/0106.从中序与后序遍历序列构造二叉树.md
index cf5f11d0..e5cbeda3 100644
--- a/problems/0106.从中序与后序遍历序列构造二叉树.md
+++ b/problems/0106.从中序与后序遍历序列构造二叉树.md
@@ -1141,22 +1141,19 @@ object Solution {
 106 从中序与后序遍历序列构造二叉树
 
 ```rust
+use std::cell::RefCell;
+use std::rc::Rc;
 impl Solution {
-    pub fn build_tree(
-        mut inorder: Vec<i32>,
-        mut postorder: Vec<i32>,
-    ) -> Option<Rc<RefCell<TreeNode>>> {
+    pub fn build_tree(inorder: Vec<i32>, postorder: Vec<i32>) -> Option<Rc<RefCell<TreeNode>>> {
         if inorder.is_empty() {
             return None;
         }
+        let mut postorder = postorder;
         let root = postorder.pop().unwrap();
         let index = inorder.iter().position(|&x| x == root).unwrap();
         let mut root = TreeNode::new(root);
-        root.left = Self::build_tree(
-            inorder.splice(0..index, []).collect(),
-            postorder.splice(0..index, []).collect(),
-        );
-        root.right = Self::build_tree(inorder.split_off(1), postorder);
+        root.left = Self::build_tree(inorder[..index].to_vec(), postorder[..index].to_vec());
+        root.right = Self::build_tree(inorder[index + 1..].to_vec(), postorder[index..].to_vec());
         Some(Rc::new(RefCell::new(root)))
     }
 }
@@ -1168,21 +1165,18 @@ impl Solution {
 use std::cell::RefCell;
 use std::rc::Rc;
 impl Solution {
-    pub fn build_tree(
-        mut preorder: Vec<i32>,
-        mut inorder: Vec<i32>,
-    ) -> Option<Rc<RefCell<TreeNode>>> {
+    pub fn build_tree(preorder: Vec<i32>, inorder: Vec<i32>) -> Option<Rc<RefCell<TreeNode>>> {
         if preorder.is_empty() {
             return None;
         }
         let root = preorder[0];
         let index = inorder.iter().position(|&x| x == root).unwrap();
         let mut root = TreeNode::new(root);
-        root.left = Self::build_tree(
-            preorder.splice(1..index + 1, []).collect(),
-            inorder.splice(0..index, []).collect(),
+        root.left = Self::build_tree(preorder[1..index + 1].to_vec(), inorder[0..index].to_vec());
+        root.right = Self::build_tree(
+            preorder[index + 1..].to_vec(),
+            inorder[index + 1..].to_vec(),
         );
-        root.right = Self::build_tree(preorder.split_off(1), inorder.split_off(1));
         Some(Rc::new(RefCell::new(root)))
     }
 }