Remove duplicates in a slice

main.go

func removeDuplicates(elements []string) []string {   // change string to int here if required
	// Use map to record duplicates as we find them.
	encountered := map[string]bool{}                   // change string to int here if required
	result := []string{}                               // change string to int here if required

	for v := range elements {
		if encountered[elements[v]] == true {
			// Do not add duplicate.
		} else {
			// Record this element as an encountered element.
			encountered[elements[v]] = true
			// Append to result slice.
			result = append(result, elements[v])
		}
	}
	// Return the new slice.
	return result
}

// usage: removeDuplicates(slice)

//Non - in - place modification, output to duplicate results and duplicates
func RemoveDuplicates2(s []string) ([]string, []string){
	//使用map[string]struct{}进行记录重复项,空的struct{}节省内存
	encountered := make(map[string]struct{})
	result := make([]string, 0)  //make初始化slice，必须给定长度
	duplicate := make([]string, 0)
	for _, v := range s {
		if _, ok := encountered[v]; ok{
			duplicate = append(duplicate, v)  //append是否比slice[index]更快
			continue
		}else {
			encountered[v] = struct{}{}
			result = append(result, v)
		}
	}
	return result, duplicate
}