297.二叉树的序列化与反序列化
297.二叉树的序列化与反序列化
题解
题目：给你一个二叉树，序列化从一个string字符串，再从一个string字符串还原出二叉树
思路：
1.序列化：前序遍历，根左右
2.反序列化：递归，根左右
代码
type TreeNode struct {
Val int
Left *TreeNode
Right *TreeNode
}
type Codec struct{}
func Constructor() (_ Codec) {
return
}
func (Codec) serialize(root *TreeNode) string {
ss := make([]string, 0)
var dfs func(*TreeNode)
dfs = func(root *TreeNode) {
if root == nil {
ss = append(ss, "null")
return
}
ss = append(ss, strconv.Itoa(root.Val))
dfs(root.Left)
dfs(root.Right)
}
dfs(root)
return strings.Join(ss, ",")
}
func (Codec) deserialize(data string) *TreeNode {
ss := strings.Split(data, ",")
var build func() *TreeNode
build = func() *TreeNode {
if ss[0] == "null" {
ss = ss[1:]
return nil
}
val, _ := strconv.Atoi(ss[0])
ss = ss[1:]
return &TreeNode{val, build(), build()}
}
return build()
}
