Create Design A Leaderboard.java

varunu28 · web-flow · commit 2486a234e4ea · 2019-11-27T08:53:08.000-08:00
diff --git a/Medium/Design A Leaderboard.java b/Medium/Design A Leaderboard.java
@@ -0,0 +1,45 @@
+class Leaderboard {
+    Map<Integer, Integer> scoreMap;
+    Map<Integer, Set<Integer>> playerMap;
+    public Leaderboard() {
+        scoreMap = new HashMap<>();
+        playerMap = new TreeMap<>(Collections.reverseOrder());
+    }
+
+    public void addScore(int playerId, int score) {
+        if (scoreMap.containsKey(playerId)) {
+            int prevScore = scoreMap.get(playerId);
+            playerMap.get(prevScore).remove(playerId);
+        }
+        scoreMap.put(playerId, scoreMap.getOrDefault(playerId, 0) + score);
+        playerMap.computeIfAbsent(scoreMap.get(playerId), k -> new HashSet<>()).add(playerId);
+    }
+
+    public int top(int K) {
+        int sum = 0;
+        for (Integer key : playerMap.keySet()) {
+            int count = Math.min(K, playerMap.get(key).size());
+            sum += key * count;
+            K -= count;
+            if (K == 0) {
+                break;
+            }
+        }
+        return sum;
+    }
+
+    public void reset(int playerId) {
+        int prevScore = scoreMap.get(playerId);
+        playerMap.get(prevScore).remove(playerId);
+        scoreMap.put(playerId, 0);
+        playerMap.computeIfAbsent(0, k -> new HashSet<>()).add(playerId);
+    }
+}
+
+/**
+ * Your Leaderboard object will be instantiated and called as such:
+ * Leaderboard obj = new Leaderboard();
+ * obj.addScore(playerId,score);
+ * int param_2 = obj.top(K);
+ * obj.reset(playerId);
+ */
