Calculate Active Hours for Twitter Spaces

Given the following records (operation, twitter_space, user, timestamp), return the total active hours of each Twitter space. Input: ["create", "abc", "user_1", "1234567000"] ["join", "abc", "user_2", "1234567100"] ["leave", "abc", "user_2", "1234567300"] ["create", "def", "user_2", "1234568000"] ["leave", "def", "user_2", "1234568500"] ["leave", "abc", "user_1", "1234569000"] Output: {"abc": 2200, "def": 500} Explanation: user1 stayed in 'abc' for a total of 2000, user2 stayed in 'abc' for a total of 200, user2 stayed in 'def' for a total of 500. Follow-up: Generate top-k spaces with the largest number of users in real-time. Example Input ["create", "abc", "user_1", "1234567000"] ["join", "abc", "user_2", "1234567100"] ["leave", "abc", "user_2", "1234567300"] ["create", "def", "user_2", "1234568000"] ["leave", "def", "user_2", "1234568500"] ["leave", "abc", "user_1", "1234569000"] Output {"abc": 2200, "def": 500}