golang入门笔记——排序

sort包解读

一维数组排序

func main() {
	a := []int{4, 3, 2, 1, 5, 6}
	sort.Sort(sort.IntSlice(a))  //正序
	sort.Sort(sort.Reverse(sort.IntSlice(a))) //倒序
}

二维数组排序：

我们给定一个排序规则：安装第index列大小进行排序，当第index列出现值相等时，参照index+1列。

package main

import (
	"fmt"
	"sort"
)

type IntArray struct {
	array    [][]int
	firstnum int
}

func (arr *IntArray) Len() int {
	return len(arr.array)
}

func (arr *IntArray) Swap(i, j int) {
	arr.array[i], arr.array[j] = arr.array[j], arr.array[i]
}

func (arr *IntArray) Less(i, j int) bool {
	arr1 := arr.array[i]
	arr2 := arr.array[j]
	for index := arr.firstnum; index < len(arr.array); index++ {
		if arr1[index] < arr2[index] {
			return true
		} else if arr1[index] > arr2[index] {
			return false
		}
	}
	return i < j
} //自定义排序方法

func ArraySort(array [][]int, first int) [][]int {
	arr := &IntArray{array, first}
	sort.Sort(arr)
	return arr.array
}

func main() {
	nums := [][]int{{1, 9, 5}, {2, 3, 6}, {3, 6, 9}, {1, 8, 3}}
	firIndex := 2
	result := ArraySort(nums, firIndex-1)
	fmt.Println(result)
}

//输出[[2 3 6] [3 6 9] [1 8 3] [1 9 5]]

//另一种写法
func main() {
	nums := [][]int{{1, 9, 5}, {2, 3, 6}, {3, 6, 9}, {1, 8, 3}}
	firIndex := 2
	sort.Slice(nums, func(i, j int) bool {
		arr1 := nums[i]
		arr2 := nums[j]
		for index := firIndex - 1; index < len(nums); index++ {
			if arr1[index] < arr2[index] {
				return true
			} else if arr1[index] > arr2[index] {
				return false
			}
		}
		return i < j
	})
	fmt.Println(nums)
}

结构体排序

package main

import (
	"fmt"
	"sort"
)

type User struct {
	Name string
	Age  int
}

func main() {
	member := []User{
		{"zyj", 22},
		{"zyj0", 21},
		{"zyj1", 23},
	}
	sort.Slice(member, func(i, j int) bool {
		return member[i].Age < member[j].Age
	})
	fmt.Println(member)
}