Find Followers Count

Task: Write a solution that will, for each user, return the number of followers. Order the result by user_id.

Table: Followers

+-------------+------+
| Column Name | Type |
+-------------+------+
| user_id     | INT  |
| follower_id | INT  |
+-------------+------+

Input: Followers table:

+---------+-------------+
| user_id | follower_id |
+---------+-------------+
| 0       | 1           |
| 1       | 0           |
| 2       | 0           |
| 2       | 1           |
+---------+-------------+

Output:

+---------+-----------------+
| user_id | followers_count |
+---------+-----------------+
| 0       | 1               |
| 1       | 1               |
| 2       | 2               |
+---------+-----------------+