Go Custom sort

C++ Implement custom sorting in , Can be in sort On the last parameter bit of the function , Add a Customized ratio function perhaps functor To achieve ：

lambda expression

// v yes vector<int> type 
sort(v.begin(), v.end(), [](int a, int b) {
    
     return a > b;
});

functor

class SortInt {
    
public:
     bool operator() (int a, int b) {
    
         return a > b;
     }
};
sort(v.begin(), v.end(), SortInt());

Go Through... In language sort Interfaces and functions provided by the package , You can also customize sorting .

Three basic types of ascending sort

If the slice to be sorted is int64, float64, string type , And it is sorted in ascending order , You can use the following three functions to sort ：

sort.Ints(x []int)
sort.Float64s(x []float64)
sort.Strings(x []string)

sort.Sort(data Interface)

This function can sort slices of custom types , The premise is that this custom type must be implemented Interface Interface .

Interface

type Interface interface {
    
	Len() int
	Less(i, j int) bool
	Swap(i, j int)
}

int Examples of types

type sortInt []int

func (arr sortInt) Len() int {
    
	return len(arr)
}
func (arr sortInt) Less(i, j int) bool {
    
	return arr[i] < arr[j]
}

func (arr sortInt) Swap(i, j int) {
    
	arr[i], arr[j] = arr[j], arr[i]
}

func main() {
    
	arr := []int{
    1, 4, 6, 3, 10}
	var _arr sortInt = arr
	sort.Sort(_arr)
	sort.Sort(sort.Reverse(_arr))  //  Reverse order 
}

struct Examples of types

type Students []Student

func (s Students) Len() int {
    
	return len(s)
}
func (s Students) Less(i, j int) bool {
    
	return s[i].score < s[j].score
}
func (s Students) Swap(i, j int) {
    
	s[i], s[j] = s[j], s[i]
}

func main() {
    
	var students Students
	students = []Student{
    
		Student{
    "zhangsan", 89},
		Student{
    "lisi", 98},
		Student{
    "wangwu", 78},
	}
	sort.Sort(students)
}

sort.Slice(x interface{}, less func(i, j int) bool)

This function can sort the slice types , You also need to provide a return value of bool Function object of type .

int Examples of types

arr := []int{
    1, 4, 6, 3, 10}
sort.Slice(arr, func(i, j int) bool {
    
	return arr[i] > arr[j]
})

struct Examples of types

students := []Student{
    
		Student{
    "zhangsan", 89},
		Student{
    "lisi", 98},
		Student{
    "wangwu", 78},
}
sort.Slice(students, func(i, j int) bool {
    
	return students[i].score > students[j].score
})
fmt.Println(students)

It seems to use sort.Slice It seems more convenient , Later, we found more advanced functions and added .