Create tournament-winners.sql

Author: kamyu104

MySQL/tournament-winners.sql

@@ -0,0 +1,22 @@
+# Time:  O(m + n + nlogn)
+# Space: P(m + n)
+
+SELECT group_id, 
+       player_id 
+FROM   (SELECT p.group_id, 
+               ps.player_id, 
+               Sum(ps.score) AS score 
+        FROM   players p INNER JOIN
+               (SELECT first_player AS player_id, 
+                       first_score  AS score 
+                FROM   matches 
+                UNION ALL 
+                SELECT second_player AS player_id,
+                       second_score  AS score
+                FROM   matches) ps 
+        ON  p.player_id = ps.player_id 
+        GROUP  BY ps.player_id 
+        ORDER  BY group_id, 
+                  score DESC, 
+                  player_id) top_scores 
+GROUP  BY group_id