style: format code and docs with prettier

Author: klever34

lcp/LCP 67. 装饰树/README.md

@@ -204,7 +204,7 @@ func expandBinaryTree(root *TreeNode) *TreeNode {
 *     var val: Int
 *     var left: TreeNode?
 *     var right: TreeNode?
-    
+
 *     init() { self.val = 0; self.left = nil; self.right = nil }
 *     init(_ val: Int) { self.val = val; self.left = nil; self.right = nil }
 *     init(_ val: Int, _ left: TreeNode?, _ right: TreeNode?) {
@@ -219,20 +219,20 @@ class Solution {
     func expandBinaryTree(_ root: TreeNode?) -> TreeNode? {
         return dfs(root)
     }
-    
+
     private func dfs(_ root: TreeNode?) -> TreeNode? {
         guard let root = root else { return nil }
-        
+
         let leftChild = dfs(root.left)
         let rightChild = dfs(root.right)
-        
+
         if let leftChild = leftChild {
             root.left = TreeNode(-1, leftChild, nil)
         }
         if let rightChild = rightChild {
             root.right = TreeNode(-1, nil, rightChild)
         }
-        
+
         return root
     }
 }