feat: add paid only questions

solution/0500-0599/0511.Game Play Analysis I/README.md

@@ -6,7 +6,49 @@
 
 <!-- 这里写题目描述 -->
 
-None
+<p>活动表&nbsp;<code>Activity</code>：</p>
+
+<pre>
++--------------+---------+
+| Column Name  | Type    |
++--------------+---------+
+| player_id    | int     |
+| device_id    | int     |
+| event_date   | date    |
+| games_played | int     |
++--------------+---------+
+表的主键是 (player_id, event_date)。
+这张表展示了一些游戏玩家在游戏平台上的行为活动。
+每行数据记录了一名玩家在退出平台之前，当天使用同一台设备登录平台后打开的游戏的数目（可能是 0 个）。
+</pre>
+
+<p>&nbsp;</p>
+
+<p>写一条 SQL&nbsp;查询语句获取每位玩家 <strong>第一次登陆平台的日期</strong>。</p>
+
+<p>查询结果的格式如下所示：</p>
+
+<pre>
+Activity 表：
++-----------+-----------+------------+--------------+
+| player_id | device_id | event_date | games_played |
++-----------+-----------+------------+--------------+
+| 1         | 2         | 2016-03-01 | 5            |
+| 1         | 2         | 2016-05-02 | 6            |
+| 2         | 3         | 2017-06-25 | 1            |
+| 3         | 1         | 2016-03-02 | 0            |
+| 3         | 4         | 2018-07-03 | 5            |
++-----------+-----------+------------+--------------+
+
+Result 表：
++-----------+-------------+
+| player_id | first_login |
++-----------+-------------+
+| 1         | 2016-03-01  |
+| 2         | 2017-06-25  |
+| 3         | 2016-03-02  |
++-----------+-------------+
+</pre>
 
 ## 解法
 
@@ -16,8 +58,8 @@ None
 
 ### **SQL**
 
-```
-select player_id, min(event_date) as first_login from Activity group by player_id
+```sql
+
 ```
 
 <!-- tabs:end -->

solution/0500-0599/0511.Game Play Analysis I/README_EN.md

@@ -4,16 +4,58 @@
 
 ## Description
 
-None
+<p>Table:&nbsp;<code>Activity</code></p>
+
+<pre>
++--------------+---------+
+| Column Name  | Type    |
++--------------+---------+
+| player_id    | int     |
+| device_id    | int     |
+| event_date   | date    |
+| games_played | int     |
++--------------+---------+
+(player_id, event_date) is the primary key of this table.
+This table shows the activity of players of some game.
+Each row is a record of a player who logged in and played a number of games (possibly 0) before logging out on some day using some device.
+</pre>
+
+<p>&nbsp;</p>
+
+<p>Write an SQL query that reports the&nbsp;<strong>first login date</strong> for each player.</p>
+
+<p>The query result format is in the following example:</p>
+
+<pre>
+Activity table:
++-----------+-----------+------------+--------------+
+| player_id | device_id | event_date | games_played |
++-----------+-----------+------------+--------------+
+| 1         | 2         | 2016-03-01 | 5            |
+| 1         | 2         | 2016-05-02 | 6            |
+| 2         | 3         | 2017-06-25 | 1            |
+| 3         | 1         | 2016-03-02 | 0            |
+| 3         | 4         | 2018-07-03 | 5            |
++-----------+-----------+------------+--------------+
+
+Result table:
++-----------+-------------+
+| player_id | first_login |
++-----------+-------------+
+| 1         | 2016-03-01  |
+| 2         | 2017-06-25  |
+| 3         | 2016-03-02  |
++-----------+-------------+
+</pre>
 
 ## Solutions
 
 <!-- tabs:start -->
 
 ### **SQL**
 
-```
-select player_id, min(event_date) as first_login from Activity group by player_id
+```sql
+
 ```
 
 <!-- tabs:end -->

solution/0500-0599/0512.Game Play Analysis II/README.md

@@ -6,7 +6,46 @@
 
 <!-- 这里写题目描述 -->
 
-None
+<p>Table:&nbsp;<code>Activity</code></p>
+
+<pre>
++--------------+---------+
+| Column Name  | Type    |
++--------------+---------+
+| player_id    | int     |
+| device_id    | int     |
+| event_date   | date    |
+| games_played | int     |
++--------------+---------+
+(player_id, event_date) 是这个表的两个主键
+这个表显示的是某些游戏玩家的游戏活动情况
+每一行是在某天使用某个设备登出之前登录并玩多个游戏（可能为0）的玩家的记录
+</pre>
+
+<p>请编写一个 SQL 查询，描述每一个玩家首次登陆的设备名称</p>
+
+<p>查询结果格式在以下示例中：</p>
+
+<pre>
+Activity table:
++-----------+-----------+------------+--------------+
+| player_id | device_id | event_date | games_played |
++-----------+-----------+------------+--------------+
+| 1         | 2         | 2016-03-01 | 5            |
+| 1         | 2         | 2016-05-02 | 6            |
+| 2         | 3         | 2017-06-25 | 1            |
+| 3         | 1         | 2016-03-02 | 0            |
+| 3         | 4         | 2018-07-03 | 5            |
++-----------+-----------+------------+--------------+
+
+Result table:
++-----------+-----------+
+| player_id | device_id |
++-----------+-----------+
+| 1         | 2         |
+| 2         | 3         |
+| 3         | 1         |
++-----------+-----------+</pre>
 
 ## 解法
 
@@ -16,8 +55,8 @@ None
 
 ### **SQL**
 
-```
-select player_id, device_id from Activity where (player_id, event_date) in ((select player_id, min(event_date) from Activity group by player_id))
+```sql
+
 ```
 
 <!-- tabs:end -->

solution/0500-0599/0512.Game Play Analysis II/README_EN.md

@@ -4,16 +4,57 @@
 
 ## Description
 
-None
+<p>Table:&nbsp;<code>Activity</code></p>
+
+<pre>
++--------------+---------+
+| Column Name  | Type    |
++--------------+---------+
+| player_id    | int     |
+| device_id    | int     |
+| event_date   | date    |
+| games_played | int     |
++--------------+---------+
+(player_id, event_date) is the primary key of this table.
+This table shows the activity of players of some game.
+Each row is a record of a player who logged in and played a number of games (possibly 0) before logging out on some day using some device.
+</pre>
+
+<p>&nbsp;</p>
+
+<p>Write a&nbsp;SQL query that reports&nbsp;the <strong>device</strong>&nbsp;that is first logged in&nbsp;for each player.</p>
+
+<p>The query result format is in the following example:</p>
+
+<pre>
+Activity table:
++-----------+-----------+------------+--------------+
+| player_id | device_id | event_date | games_played |
++-----------+-----------+------------+--------------+
+| 1         | 2         | 2016-03-01 | 5            |
+| 1         | 2         | 2016-05-02 | 6            |
+| 2         | 3         | 2017-06-25 | 1            |
+| 3         | 1         | 2016-03-02 | 0            |
+| 3         | 4         | 2018-07-03 | 5            |
++-----------+-----------+------------+--------------+
+
+Result table:
++-----------+-----------+
+| player_id | device_id |
++-----------+-----------+
+| 1         | 2         |
+| 2         | 3         |
+| 3         | 1         |
++-----------+-----------+</pre>
 
 ## Solutions
 
 <!-- tabs:start -->
 
 ### **SQL**
 
-```
-select player_id, device_id from Activity where (player_id, event_date) in ((select player_id, min(event_date) from Activity group by player_id))
+```sql
+
 ```
 
 <!-- tabs:end -->

solution/0500-0599/0534.Game Play Analysis III/README.md

@@ -6,7 +6,54 @@
 
 <!-- 这里写题目描述 -->
 
-None
+<p>Table:&nbsp;<code>Activity</code></p>
+
+<pre>
++--------------+---------+
+| Column Name  | Type    |
++--------------+---------+
+| player_id    | int     |
+| device_id    | int     |
+| event_date   | date    |
+| games_played | int     |
++--------------+---------+
+（player_id，event_date）是此表的主键。
+这张表显示了某些游戏的玩家的活动情况。
+每一行是一个玩家的记录，他在某一天使用某个设备注销之前登录并玩了很多游戏（可能是 0 ）。
+</pre>
+
+<p>&nbsp;</p>
+
+<p>编写一个 SQL 查询，同时报告每组玩家和日期，以及玩家到目前为止玩了多少游戏。也就是说，在此日期之前玩家所玩的游戏总数。详细情况请查看示例。</p>
+
+<p>查询结果格式如下所示：</p>
+
+<pre>
+Activity table:
++-----------+-----------+------------+--------------+
+| player_id | device_id | event_date | games_played |
++-----------+-----------+------------+--------------+
+| 1         | 2         | 2016-03-01 | 5            |
+| 1         | 2         | 2016-05-02 | 6            |
+| 1         | 3         | 2017-06-25 | 1            |
+| 3         | 1         | 2016-03-02 | 0            |
+| 3         | 4         | 2018-07-03 | 5            |
++-----------+-----------+------------+--------------+
+
+Result table:
++-----------+------------+---------------------+
+| player_id | event_date | games_played_so_far |
++-----------+------------+---------------------+
+| 1         | 2016-03-01 | 5                   |
+| 1         | 2016-05-02 | 11                  |
+| 1         | 2017-06-25 | 12                  |
+| 3         | 2016-03-02 | 0                   |
+| 3         | 2018-07-03 | 5                   |
++-----------+------------+---------------------+
+对于 ID 为 1 的玩家，2016-05-02 共玩了 5+6=11 个游戏，2017-06-25 共玩了 5+6+1=12 个游戏。
+对于 ID 为 3 的玩家，2018-07-03 共玩了 0+5=5 个游戏。
+请注意，对于每个玩家，我们只关心玩家的登录日期。
+</pre>
 
 ## 解法
 
@@ -16,8 +63,8 @@ None
 
 ### **SQL**
 
-```
-select a.player_id, a.event_date, sum(b.games_played) as games_played_so_far from Activity a, Activity b where a.player_id = b.player_id and a.event_date >= b.event_date group by a.player_id, a.event_date
+```sql
+
 ```
 
 <!-- tabs:end -->

solution/0500-0599/0534.Game Play Analysis III/README_EN.md

@@ -4,16 +4,63 @@
 
 ## Description
 
-None
+<p>Table:&nbsp;<code>Activity</code></p>
+
+<pre>
++--------------+---------+
+| Column Name  | Type    |
++--------------+---------+
+| player_id    | int     |
+| device_id    | int     |
+| event_date   | date    |
+| games_played | int     |
++--------------+---------+
+(player_id, event_date) is the primary key of this table.
+This table shows the activity of players of some game.
+Each row is a record of a player who logged in and played a number of games (possibly 0) before logging out on some day using some device.
+</pre>
+
+<p>&nbsp;</p>
+
+<p>Write an SQL query that reports for each player and date, how many games played&nbsp;<strong>so far</strong>&nbsp;by the player. That is, the total number of games played by the player until that date. Check the example for clarity.</p>
+
+<p>The query result format is in the following example:</p>
+
+<pre>
+Activity table:
++-----------+-----------+------------+--------------+
+| player_id | device_id | event_date | games_played |
++-----------+-----------+------------+--------------+
+| 1         | 2         | 2016-03-01 | 5            |
+| 1         | 2         | 2016-05-02 | 6            |
+| 1         | 3         | 2017-06-25 | 1            |
+| 3         | 1         | 2016-03-02 | 0            |
+| 3         | 4         | 2018-07-03 | 5            |
++-----------+-----------+------------+--------------+
+
+Result table:
++-----------+------------+---------------------+
+| player_id | event_date | games_played_so_far |
++-----------+------------+---------------------+
+| 1         | 2016-03-01 | 5                   |
+| 1         | 2016-05-02 | 11                  |
+| 1         | 2017-06-25 | 12                  |
+| 3         | 2016-03-02 | 0                   |
+| 3         | 2018-07-03 | 5                   |
++-----------+------------+---------------------+
+For the player with id 1, 5 + 6 = 11 games played by 2016-05-02, and 5 + 6 + 1 = 12 games played by 2017-06-25.
+For the player with id 3, 0 + 5 = 5 games played by 2018-07-03.
+Note that for each player we only care about the days when the player logged in.
+</pre>
 
 ## Solutions
 
 <!-- tabs:start -->
 
 ### **SQL**
 
-```
-select a.player_id, a.event_date, sum(b.games_played) as games_played_so_far from Activity a, Activity b where a.player_id = b.player_id and a.event_date >= b.event_date group by a.player_id, a.event_date
+```sql
+
 ```
 
 <!-- tabs:end -->