Rules

• Every user has exactly one team; teams contain one or more player IDs.
• A player may belong to multiple users’ teams (many-to-many relation).
• Each user’s initial score is 0 (before any player points are applied).
• Player score updates are deltas and may be negative or positive.
• User score = sum of scores of all players currently in that user’s team.
• Leaderboard ordering:
  1. Primary: user score in descending order (higher is better).
  2. Tie-break: userId in lexicographically ascending order.

Methods

void addUser(String userId, List<String> playerIds)

• userId will always be globally unique and non-blank.
• playerIds will contain at least one element; each playerId is non-blank and valid.
• Effect: registers a new user with their team and an initial score of 0.
• Players may already have accrued points from prior updates; the user’s score should immediately reflect the current player scores after registration.

void addScore(String playerId, int score)

• Updates the specified player’s cumulative score by the given delta.
• score is an integer in the inclusive range [-1000, 1000].
• All users whose team includes playerId must have their team scores updated accordingly.
• Leaderboard ordering must remain consistent with the updated scores.

List<String> getTopK(int k)

• k >= 1. If k exceeds the total number of users, return all users.
• Return the list of userId values sorted by:
  1. Score descending, then
  2. userId lexicographically ascending to break ties.

Example

// Sequence (illustrative):

addUser("uA", ["p1", "p2"])
addUser("uB", ["p2"])
getTopK(2)              // ["uA", "uB"]  // both 0; "uA" < "uB"

addScore("p2", 10)      // p2 = 10; uA=10 (p1=0 + p2=10), uB=10
getTopK(2)              // ["uA", "uB"]  // tie by score, lex by userId

addScore("p1", 3)       // p1 = 3; uA=13, uB=10
getTopK(1)              // ["uA"]

addScore("p2", -5)      // p2 = 5; uA=8 (3+5), uB=5
getTopK(5)              // return all users: ["uA", "uB"]