I wrote solution using Oracle SQL
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```oraclesql []\nwith CTE as(\n    SELECT PLAYER_ID, MIN(EVENT_DATE) AS FRST_DATE\n    FROM Activity\n    GROUP BY PLAYER_ID),\nCON AS(\n    SELECT A.PLAYER_ID AS PLAYER_ID\n    FROM Activity A\n    JOIN\n    cte ON A.PLAYER_ID = CTE.PLAYER_ID\n    WHERE A.EVENT_DATE=CTE.FRST_DATE + 1\n)\n-- SELECT * FROM CTE;\n-- SELECT * FROM CON;\n\nSELECT ROUND(COUNT(DISTINCT CON.PLAYER_ID)/COUNT(CTE.PLAYER_ID),2) AS fraction FROM\nCTE LEFT JOIN CON ON CON.PLAYER_ID = CTE.PLAYER_ID;\n\n\n```
['Oracle']