Taken from Execute Program
Write a
SocialGraphclass with a constructor and two methods.
- The constructor creates an empty
Map.- The
addFollowmethod records thatuser1followsuser2by updating the map. Note that order matters here- The
followsmethod checks for whetheruser1followsuser2, returning aboolean.
Solution
This is the answer I came up with:
interface SocialGraph {
map: Map<string, string[]>
}
class SocialGraph {
constructor() {
this.map = new Map()
}
addFollow(user1: string, user2: string) {
// If user2 isn't present, create a user2 key in the map
if (!this.map.has(user2)) {
this.map.set(user2, [])
}
// Get the array of users of user1, and add user1
this.map.get(user2).push(user1)
}
follows(user1: string, user2: string) {
// If user2 doesn't exist, return false
if (!this.map.has(user2)) { return false }
// Otherwise get the array of users of user2, and check if it includes user1
return this.map.get(user2).includes(user1)
}
}