Question

当然，人们总是可以写一个for循环。但代码共享通常总是很好。那么有没有办法编写一个排序任何数组的方法？此外，表现，所以我猜测排除反思。

sort.Reverse似乎无法奏效。以下内容无法编译：

package main

import (
    "fmt"
    "sort"
)

type A struct {
    X int
}

func main() {
x := make([]A, 0)
x = append(x, A{1})
x = append(x, A{2})
sort.Reverse(sort.IntSlice(x))
fmt.Println(x)
}

Answer 1

[]A is not an int slice, it's a slice of structs and you must implement a sort.Interface to describe how to sort it.

Here's a working example:

package main

import (
    "fmt"
    "sort"
)

type A struct {
    X int
}

type ByX []A

func (a ByX) Len() int           { return len(a) }
func (a ByX) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
func (a ByX) Less(i, j int) bool { return a[i].X < a[j].X }

func main() {
    x := make([]A, 0)
    x = append(x, A{1})
    x = append(x, A{2})
    sort.Sort(sort.Reverse(ByX(x)))
    fmt.Println(x)
}

Try it on the Go playground.

Alternatively, you can call sort.Slice and provide it with only the Less function:

sort.Slice(x, func(i, j int) bool { return x[i].X > x[j].X })

You should notice that the less function is different. Since we want to sort in reverse and the shorthand sort.Slice isn't compatible with sort.Reverse, we had to modify the less function to return the opposite (> instead of <).

如何反转任意数组？

1 个答案: