LeetCode-Solutions/MySQL/page-recommendations.sql at master · HappyCoderGit/LeetCode-Solutions · GitHub

16 lines (15 loc) · 566 Bytes

# Time: O(m + n)

# Space: O(m)

SELECT DISTINCT page_id AS recommended_page

FROM likes l2

WHERE NOT EXISTS (SELECT *

FROM likes l1

WHERE l1.user_id = 1

AND l1.page_id = l2.page_id)

AND user_id IN (SELECT user2_id AS friend_id

FROM friendship

WHERE user1_id = 1

UNION

SELECT user1_id AS friend_id

FROM friendship

WHERE user2_id = 1)

Expand file tree