hello-algo/codes/go/pkg/tree_node.go
Yudong Jin ebf9024136 Add Go codes to docs, including
the chapter of stack and queue, the chapter of tree.
2022-12-03 20:25:24 +08:00

73 lines
1.3 KiB
Go

// File: tree_node.go
// Created Time: 2022-11-25
// Author: Reanon (793584285@qq.com)
package pkg
import (
"container/list"
)
type TreeNode struct {
Val int
Left *TreeNode
Right *TreeNode
}
func NewTreeNode(v int) *TreeNode {
return &TreeNode{
Left: nil,
Right: nil,
Val: v,
}
}
// ArrayToTree Generate a binary tree with an array
func ArrayToTree(arr []int) *TreeNode {
if len(arr) <= 0 {
return nil
}
root := NewTreeNode(arr[0])
// Let container.list as queue
queue := list.New()
queue.PushBack(root)
i := 1
for queue.Len() > 0 {
// poll
node := queue.Remove(queue.Front()).(*TreeNode)
if i < len(arr) {
node.Left = NewTreeNode(arr[i])
queue.PushBack(node.Left)
i++
}
if i < len(arr) {
node.Right = NewTreeNode(arr[i])
queue.PushBack(node.Right)
i++
}
}
return root
}
// TreeToArray Serialize a binary tree to a list
func TreeToArray(root *TreeNode) []any {
if root == nil {
return []any{}
}
arr := make([]any, 0)
queue := list.New()
queue.PushBack(root)
for queue.Len() > 0 {
node := queue.Remove(queue.Front()).(*TreeNode)
if node != nil {
arr = append(arr, node.Val)
queue.PushBack(node.Left)
queue.PushBack(node.Right)
} else {
// node don't exist.
arr = append(arr, nil)
}
}
return arr
}