golang 树结构化

最近编写员工分组的组织架构树,记录一下两种方式：

递归框架

递归方法优缺点：

　　优点：代码较少；

　　缺点：性能较差；

树函数(列表，父ID)
   ret = []
   for 节点 in 列表:
        if 节点的parent_id 等于 父ID
            节点.children = 获取树(列表, 节点ID)
            ret = append(ret,节点)
   return ret

package main

import (
    "encoding/json"
    "fmt"
)

type Node struct {
    Id       int     `json:"id"`
    ParentId int     `json:"parent_id"`
    Name     string  `json:"name"`
    Children []*Node `json:"children"`
}

func getTreeRecursive(list []*Node, parentId int) []*Node {
    res := make([]*Node, 0)
    for _, v := range list {
        if v.ParentId == parentId {
            v.Children = getTreeRecursive(list, v.Id)
            res = append(res, v)
        }
    }
    return res
}

func main() {
    list := []*Node{
        {4, 3, "ABA", nil},
        {3, 1, "AB", nil},
        {1, 0, "A", nil},
        {2, 1, "AA", nil},
    }
    res := getTreeRecursive(list, 0)
    bytes, _ := json.MarshalIndent(res, "", "    ")
    fmt.Printf("%s
", bytes)
}

　　

迭代框架

 本质是创建一条引用链，将所有的节点串起来

获取树(列表，父ID)
   memo = {}
   for 节点 in 列表:
        //构造memo给节点的父ID查找追加节点用
        if 节点ID in memo:
            节点.children = memo[节点ID].children //之前构造的children数组覆盖当前节点的children
            memo[节点ID] = 节点
        else
            节点.children = []
            memo[节点ID] = 节点
        
        //给像父对象的children追加
        if 节点父ID in memo:
            memo[节点父ID].children.add(memo[节点ID]) //追加当前构造的ID节点
        else:
            memo[节点父ID] = {'children':[memo[节点ID]]} //初始化父对象再追加
            
   return memo[父ID].children

package main

import (
    "encoding/json"
    "fmt"
)

type Node struct {
    Id       int     `json:"id"`
    ParentId int     `json:"parent_id"`
    Name     string  `json:"name"`
    Children []*Node `json:"children"`
}

func getTreeIterative(list []*Node, parentId int) []*Node {
    memo := make(map[int]*Node)
    for _, v := range list {
        if _, ok := memo[v.Id]; ok {
            v.Children = memo[v.Id].Children
            memo[v.Id] = v
        } else {
            v.Children = make([]*Node, 0)
            memo[v.Id] = v
        }
        if _, ok := memo[v.ParentId]; ok {
            memo[v.ParentId].Children = append(memo[v.ParentId].Children, memo[v.Id])
        } else {
            memo[v.ParentId] = &Node{Children: []*Node{memo[v.Id]}}
        }
    }
    return memo[parentId].Children

}

func main() {
    list := []*Node{
        {4, 3, "ABA", nil},
        {3, 1, "AB", nil},
        {1, 0, "A", nil},
        {2, 1, "AA", nil},
        {5, 3, "ABB", nil},
}
    res := getTreeIterative(list, 0)
    bytes, _ := json.MarshalIndent(res, "", "    ")
    fmt.Printf("%s
", bytes)
}

参考文献