Update solution 297

leetcode/0297.Serialize-and-Deserialize-Binary-Tree/297.Serialize and Deserialize Binary Tree.go

@@ -11,7 +11,7 @@ type TreeNode = structures.TreeNode
 
 type Codec struct {
 	builder strings.Builder
-	input []string
+	input   []string
 }
 
 func Constructor() Codec {
@@ -24,11 +24,9 @@ func (this *Codec) serialize(root *TreeNode) string {
 		this.builder.WriteString("#,")
 		return ""
 	}
-
-	this.builder.WriteString(strconv.Itoa(root.Val)+",")
+	this.builder.WriteString(strconv.Itoa(root.Val) + ",")
 	this.serialize(root.Left)
 	this.serialize(root.Right)
-
 	return this.builder.String()
 }
 
@@ -46,13 +44,11 @@ func (this *Codec) deserializeHelper() *TreeNode {
 		this.input = this.input[1:]
 		return nil
 	}
-
 	val, _ := strconv.Atoi(this.input[0])
 	this.input = this.input[1:]
-
 	return &TreeNode{
-		Val: val,
-		Left: this.deserializeHelper(),
+		Val:   val,
+		Left:  this.deserializeHelper(),
 		Right: this.deserializeHelper(),
 	}
-}
+}

leetcode/0297.Serialize-and-Deserialize-Binary-Tree/README.md

@@ -1,45 +1,48 @@
 # [297. Serialize and Deserialize Binary Tree](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/)
 
+
 ## 题目
 
 Serialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in a file or memory buffer, or transmitted across a network connection link to be reconstructed later in the same or another computer environment.
 
 Design an algorithm to serialize and deserialize a binary tree. There is no restriction on how your serialization/deserialization algorithm should work. You just need to ensure that a binary tree can be serialized to a string and this string can be deserialized to the original tree structure.
 
-**Clarification:** The input/output format is the same as how LeetCode serializes a binary tree. You do not necessarily need to follow this format, so please be creative and come up with different approaches yourself.
+**Clarification:** The input/output format is the same as [how LeetCode serializes a binary tree](https://leetcode.com/faq/#binary-tree). You do not necessarily need to follow this format, so please be creative and come up with different approaches yourself.
 
-Example 1:
+**Example 1:**
+
+![https://assets.leetcode.com/uploads/2020/09/15/serdeser.jpg](https://assets.leetcode.com/uploads/2020/09/15/serdeser.jpg)
 
 ```
 Input: root = [1,2,3,null,null,4,5]
 Output: [1,2,3,null,null,4,5]
 ```
 
-Example 2:
+**Example 2:**
 
 ```
 Input: root = []
 Output: []
 ```
 
-Example 3:
+**Example 3:**
 
 ```
 Input: root = [1]
 Output: [1]
 ```
 
-Example 4:
+**Example 4:**
 
 ```
 Input: root = [1,2]
 Output: [1,2]
 ```
 
-Constraints:
+**Constraints:**
 
-* The number of nodes in the tree is in the range [0, 104].
-* -1000 <= Node.val <= 1000
+- The number of nodes in the tree is in the range `[0, 104]`.
+- `1000 <= Node.val <= 1000`
 
 ## 题目大意
 
@@ -47,5 +50,64 @@ Constraints:
 
 ## 解题思路
 
-1. 将给定的二叉树想象成一颗满二叉树(不存在的结点用 null 填充)。
-2. 通过前序遍历，可以得到一个第一个结点为根的序列，然后递归进行序列化/反序列化即可。
+- 1. 将给定的二叉树想象成一颗满二叉树(不存在的结点用 null 填充)。
+- 2. 通过前序遍历，可以得到一个第一个结点为根的序列，然后递归进行序列化/反序列化即可。
+
+## 代码
+
+```go
+package leetcode
+
+import (
+	"strconv"
+	"strings"
+
+	"github.com/halfrost/LeetCode-Go/structures"
+)
+
+type TreeNode = structures.TreeNode
+
+type Codec struct {
+	builder strings.Builder
+	input   []string
+}
+
+func Constructor() Codec {
+	return Codec{}
+}
+
+// Serializes a tree to a single string.
+func (this *Codec) serialize(root *TreeNode) string {
+	if root == nil {
+		this.builder.WriteString("#,")
+		return ""
+	}
+	this.builder.WriteString(strconv.Itoa(root.Val) + ",")
+	this.serialize(root.Left)
+	this.serialize(root.Right)
+	return this.builder.String()
+}
+
+// Deserializes your encoded data to tree.
+func (this *Codec) deserialize(data string) *TreeNode {
+	if len(data) == 0 {
+		return nil
+	}
+	this.input = strings.Split(data, ",")
+	return this.deserializeHelper()
+}
+
+func (this *Codec) deserializeHelper() *TreeNode {
+	if this.input[0] == "#" {
+		this.input = this.input[1:]
+		return nil
+	}
+	val, _ := strconv.Atoi(this.input[0])
+	this.input = this.input[1:]
+	return &TreeNode{
+		Val:   val,
+		Left:  this.deserializeHelper(),
+		Right: this.deserializeHelper(),
+	}
+}
+```