Group Membership

main.go

package main

import (
	"fmt"
	"strings"
)

// A group's effective members include the members for the group itself as well as all of its children. Write a function to detect if a given user is an effective member of a given group.

type Group struct {
	id      string
	members []string
	parent  string
}

func main() {
	groupList := []Group{
		Group{
			id:      "design",
			members: []string{"Jane"},
			parent:  "data",
		},
		Group{
			id:      "data",
			members: []string{"John"},
		},
		Group{
			id:      "design-leadership",
			parent:  "design",
			members: []string{"Jerry", "Mary", "Jim"},
		},
		Group{
			id:      "foo",
			parent:  "design",
			members: []string{"Mike"},
		},
		Group{
			id:      "bar",
			parent:  "foo",
			members: []string{"Mark"},
		},
	}

	fmt.Println(isMember("Mary", "design", groupList) == true)
	fmt.Println(isMember("Mark", "design", groupList) == true)
	fmt.Println(isMember("Jane", "design", groupList) == true)
	fmt.Println(isMember("Jane", "design-leadership", groupList) == false)
}

/*
 * data  - John1
 *   design - Jane
 *     design-leadership - John2 Mary Jim
 */

// isMember("Jane", "design-leadership") -> false
// isMember("John", "design") -> true
// isMember("Mary", "data") -> true
// isMember("John1", "design-leadsership") -> false

func isMember(name, groupID string, groupList []Group) bool {
	// check if in first group
	for _, group := range groupList {
		if strings.ToLower(group.id) == strings.ToLower(groupID) {
			for _, memberName := range group.members {
				if strings.ToLower(name) == strings.ToLower(memberName) {
					return true
				}
			}
		}
	}

	// if not, next check for membership in children
	childrenIDs := fetchChildrenIDs("design", groupList)
	for _, childID := range childrenIDs {
		for _, group := range groupList {
			if strings.ToLower(group.id) == strings.ToLower(childID) {
				for _, memberName := range group.members {
					if strings.ToLower(name) == strings.ToLower(memberName) {
						return true
					}
				}
			}
		}
	}

	return false
}

func fetchChildrenIDs(groupID string, groupList []Group) []string {
	var ret []string

	for _, group := range groupList {
		if strings.ToLower(groupID) == strings.ToLower(group.parent) {
			ret = append(ret, group.id)
		}
	}

	// recursive search...
	for _, tmpGroupID := range ret {
		ret = append(ret, fetchChildrenIDs(tmpGroupID, groupList)...)
	}

	return ret
}