剑指 Offer 37. 序列化二叉树
请实现两个函数，分别用来序列化和反序列化二叉树。
示例:
你可以将以下二叉树：
1
/
2 3
/
4 5序列化为 "[1,2,3,null,null,4,5]"
注意：本题与主站 297 题相同：https://leetcode-cn.com/problems/serialize-and-deserialize-binary-tree/
/**
* Definition for a binary tree node.
* type TreeNode struct {
* Val int
* Left *TreeNode
* Right *TreeNode
* }
*/
import (
"strconv"
"fmt"
)
var path string
//var u int
type Codec struct{
list []string
}
func Constructor() Codec {
return Codec{}
}
// Serializes a tree to a single string.
func (this *Codec) serialize(root *TreeNode) string {
dfsSer(root)
return path
}
func dfsSer(root *TreeNode) {
if root == nil {
path += "#,"
} else {
path += strconv.Itoa(root.Val) + ","
dfsSer(root.Left)
dfsSer(root.Right)
}
}
// Deserializes your encoded data to tree.
func (this *Codec) deserialize(data string) *TreeNode {
u := 0
return dfsDse(data, &u)
}
func dfsDse(data string, u *int) *TreeNode {
if data[*u] == '#' {
*u += 2
return nil
} else {
k := *u
for data[*u] != ',' {*u += 1}
root := &TreeNode{}
root.Val, _ = strconv.Atoi(data[k:*u])
*u += 1
root.Left = dfsDse(data, u)
root.Right = dfsDse(data, u)
return root
}
}
/**
* Your Codec object will be instantiated and called as such:
* ser := Constructor();
* deser := Constructor();
* data := ser.serialize(root);
* ans := deser.deserialize(data);
*/