Working with Sets in Go

In Go, there isn't a built-in set data type, but you can implement sets using existing data structures like maps or slices. This snippet demonstrates how to create and manipulate sets effectively.

Using Maps to Create Sets

Maps in Go can be used to mimic the behavior of sets. Here's how you can implement a simple set using a map with keys as set elements and boolean values as placeholders:

package main

import "fmt"

// StringSet represents a set of strings.
type StringSet map[string]bool

// Add inserts an element into the set.
func (s StringSet) Add(element string) {
	s[element] = true
}

// Remove deletes an element from the set.
func (s StringSet) Remove(element string) {
	delete(s, element)
}

// Contains checks if an element exists in the set.
func (s StringSet) Contains(element string) bool {
	_, exists := s[element]
	return exists
}

func main() {
	set := StringSet{}
	set.Add("golang")
	set.Add("docker")
	set.Add("kubernetes")

	fmt.Println("Set contains 'docker':", set.Contains("docker"))
	set.Remove("docker")
	fmt.Println("Set contains 'docker' after removal:", set.Contains("docker"))
}

Implementing Integer Sets with Slices

For integer sets, you may choose to use slices, providing custom functions for common set operations:

package main

import (
	"fmt"
	"sort"
)

// IntegerSet represents a set of integers.
type IntegerSet []int

// Add inserts an element into the set if it does not already exist.
func (s *IntegerSet) Add(element int) {
	if !s.Contains(element) {
		*s = append(*s, element)
		sort.Ints(*s)
	}
}

// Remove deletes an element from the set.
func (s *IntegerSet) Remove(element int) {
	for i, v := range *s {
		if v == element {
			*s = append((*s)[:i], (*s)[i+1:]...)
			return
		}
	}
}

// Contains checks if an element exists in the set.
func (s IntegerSet) Contains(element int) bool {
	i := sort.SearchInts(s, element)
	return i < len(s) && s[i] == element
}

func main() {
	set := IntegerSet{}
	set.Add(42)
	set.Add(73)
	set.Add(91)

	fmt.Println("Set contains 73:", set.Contains(73))
	set.Remove(73)
	fmt.Println("Set contains 73 after removal:", set.Contains(73))
}

Best Practices

Use `