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| 1 | +import Foundation |
| 2 | + |
| 3 | +class Twitter { |
| 4 | + |
| 5 | + var userIDAndTweetMap = [Int:[(Int, Int)]]() |
| 6 | + var followerAndfolloweeMap = [Int:Set<Int>]() // [follower: Set<followee>] |
| 7 | + let maxPost = 10 |
| 8 | + var currentTimeRef = 10000 |
| 9 | + |
| 10 | + init() { |
| 11 | + |
| 12 | + } |
| 13 | + |
| 14 | + func postTweet(_ userId: Int, _ tweetId: Int) { |
| 15 | + currentTimeRef += 1 |
| 16 | + |
| 17 | + // add tweet to user's feed |
| 18 | + userIDAndTweetMap[userId, default: [(Int, Int)]()].append((tweetId, currentTimeRef)) |
| 19 | + if userIDAndTweetMap[userId]!.count > maxPost { |
| 20 | + userIDAndTweetMap[userId]!.removeFirst() |
| 21 | + } |
| 22 | + } |
| 23 | + |
| 24 | + func getNewsFeed(_ userId: Int) -> [Int] { |
| 25 | + var allFeeds = [(Int, Int)]() |
| 26 | + |
| 27 | + if let feeds = userIDAndTweetMap[userId] { |
| 28 | + allFeeds.append(contentsOf: feeds) |
| 29 | + } |
| 30 | + |
| 31 | + if let followeeIds = followerAndfolloweeMap[userId] { |
| 32 | + for followeeId in Array(followeeIds) { |
| 33 | + if let feeds = userIDAndTweetMap[followeeId] { |
| 34 | + allFeeds.append(contentsOf: feeds) |
| 35 | + } |
| 36 | + } |
| 37 | + } |
| 38 | + allFeeds.sort { 0ドル.1 > 1ドル.1 } |
| 39 | + let feeds = allFeeds.map { 0ドル.0 } |
| 40 | + |
| 41 | + return feeds.count <= maxPost ? feeds : Array(feeds[0..<10]) |
| 42 | + } |
| 43 | + |
| 44 | + func follow(_ followerId: Int, _ followeeId: Int) { |
| 45 | + followerAndfolloweeMap[followerId, default: Set<Int>()].insert(followeeId) |
| 46 | + } |
| 47 | + |
| 48 | + func unfollow(_ followerId: Int, _ followeeId: Int) { |
| 49 | + followerAndfolloweeMap[followerId]?.remove(followeeId) |
| 50 | + } |
| 51 | +} |
| 52 | + |
| 53 | +/** |
| 54 | + * Your Twitter object will be instantiated and called as such: |
| 55 | + * let obj = Twitter() |
| 56 | + * obj.postTweet(userId, tweetId) |
| 57 | + * let ret_2: [Int] = obj.getNewsFeed(userId) |
| 58 | + * obj.follow(followerId, followeeId) |
| 59 | + * obj.unfollow(followerId, followeeId) |
| 60 | + */ |
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