go基础之自定义排序

Posted 2022-08-26 zzxiaoma

自定义排序需要先定义一个类型，然后需要实现三个接口，Len,Less,Swap这三个，分别是长度，比较，交换。

package main

import (
  "fmt"
  "sort"
)

type MyStringList []string

func (m MyStringList) Len() int 
  return len(m)



func (m MyStringList) Less(i, j int) bool 
  return m[i] < m[j]


func (m MyStringList) Swap(i, j int) 
  m[i], m[j] = m[j], m[i]


func main() 
  names := MyStringList
  "3.abc",
  "5.rty",
  "4.ade",
  "2.vbn",
  "1.ppp",

  
  sort.Sort(names)
  for _, v := range names 
    fmt.Println(v)
  

  //字符串自带排序
  strnames := []string
  "3.abc",
  "5.rty",
  "4.ade",
  "2.vbn",
  "1.ppp",
  
  sort.Strings(strnames)
  for _, v := range strnames 
  fmt.Println(v)
  

上面sort.Strings(strnames)是字符串排序，标准库已经实现的，sort.Sort(names)是自定义排序，只不过自定义的类型是字符串切片，当然也可以是其他类型。

package main

import (
    "fmt"
    "sort"
)
type HeroKind int
const (
    None HeroKind = iota
    Tank
    Assassin
    Mage
)

type Hero struct 
    Name string
    Kind HeroKind


type Heros []*Hero

func (s Heros) Len() int 
    return len(s)


func (s Heros) Less(i, j int) bool 
    if s[i].Kind != s[j].Kind 
        return s[i].Kind < s[j].Kind
    
    return s[i].Name < s[j].Name


func (s Heros) Swap(i, j int) 
    s[i], s[j] = s[j], s[i]


func main() 
    heros := Heros
        &Hero"张三", Tank,
        &Hero"李四", Assassin,
        &Hero"王五", Mage,
        &Hero"麻六", Assassin,
        &Hero"李四", Tank,
        &Hero"王五", Mage,
    
    sort.Sort(heros)
    for _, v := range heros 
        fmt.Println(v)