起因
需要在树形结构里获取子树，树形结构一般是存储一维数组，数组元素里存储子节点的指针
代码
package main
import (
"errors"
"fmt"
)
type Node struct {
Deep int
Child *Node
}
func (n *Node) GetChild() *Node {
return n.Child
}
func (n *Node) SetChild(child *Node) {
n.Child = child
}
func GetDeepChild(node *Node, level int) (*Node, error) {
if level < 0 {
return nil, errors.New("level must >= 0")
}
if level == 0 {
return node, nil
} else {
child := node.GetChild()
if child == nil {
return nil, nil
}
return GetDeepChild(child, level-1)
}
}
func main() {
root := &Node{Deep: 0}
child1 := &Node{Deep: 1}
root.SetChild(child1)
child2 := &Node{Deep: 2}
child1.SetChild(child2)
child3 := &Node{Deep: 3}
child2.SetChild(child3)
child4 := &Node{Deep: 4}
child3.SetChild(child4)
child, _ := GetDeepChild(root, 3)
fmt.Printf("child %#v\n", child) // deep 3
child, _ = GetDeepChild(root, 5)
fmt.Printf("child %#v\n", child) // nil
}