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算法题/actors-and-directors-who-cooperated-at-least-three-times.html

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+<p>Table: <code>ActorDirector</code></p>
+
+<pre>
++-------------+---------+
+| Column Name | Type    |
++-------------+---------+
+| actor_id    | int     |
+| director_id | int     |
+| timestamp   | int     |
++-------------+---------+
+timestamp is the primary key column for this table.
+</pre>
+
+<p>&nbsp;</p>
+
+<p>Write a SQL query for a report that provides the pairs <code>(actor_id, director_id)</code> where the actor has cooperated with the director at least three times.</p>
+
+<p>Return the result table in <strong>any order</strong>.</p>
+
+<p>The query result format is in the following example.</p>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> 
+ActorDirector table:
++-------------+-------------+-------------+
+| actor_id    | director_id | timestamp   |
++-------------+-------------+-------------+
+| 1           | 1           | 0           |
+| 1           | 1           | 1           |
+| 1           | 1           | 2           |
+| 1           | 2           | 3           |
+| 1           | 2           | 4           |
+| 2           | 1           | 5           |
+| 2           | 1           | 6           |
++-------------+-------------+-------------+
+<strong>Output:</strong> 
++-------------+-------------+
+| actor_id    | director_id |
++-------------+-------------+
+| 1           | 1           |
++-------------+-------------+
+<strong>Explanation:</strong> The only pair is (1, 1) where they cooperated exactly 3 times.
+</pre>