编程介的小学生 2017-08-11 12:12 采纳率: 20.5%
浏览 640
已采纳

PreQueL

Description

In some simplistic DBMS named PreQueL, the only column type allowed is CHAR(1) (a single character), and furthermore, its values are restricted to English upper-case letters ('A' to 'Z'). Table may contain up to 9 columns, numbered from 1 to 9. Tables themselves are named with lower-case English letters ('a' to 'z').

The only database query possible first joins all the tables, then selects some rows according to conditions in one of two forms: either < column>=< value> or < column1>=< column2>, for example a2=A or b1=c4. All conditions must hold simultaneously, as if they were connected by 'AND' operator.

You must write a PreQueL processor, which, given a tables and a set of conditions, will produce query result, i.e. those rows of a join satisfying all the conditions. Resulting rows must be sorted alphabetically.
Input

The first line of input file contains of two integers - number of tables T and number of conditions D.

Starting from the second line there are T tables represented with number of rows RN and number of columns CN in the first line of a table, which is followed by RN lines consisting of exactly CN characters each. D lines with conditions follow the whole set of tables.

The constraints are: 1 <= T <= 26, 1 <= D <= 50, 1 <= CN <= 9, 1 <= RN <= 1000.
Output

Output file contains result rows, one row per line. No input query will produce more than 1000 rows. The result rows are to be sorted alphabetically.
Sample Input

2 2
3 2
AX
BX
BY
2 3
ACD
BCC
a1=b1
a2=X
Sample Output

AXACD
BXBCC

  • 写回答

1条回答

  • threenewbee 2017-08-24 15:08
    关注
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论

报告相同问题?

悬赏问题

  • ¥50 导入文件到网吧的电脑并且在重启之后不会被恢复
  • ¥15 (希望可以解决问题)ma和mb文件无法正常打开,打开后是空白,但是有正常内存占用,但可以在打开Maya应用程序后打开场景ma和mb格式。
  • ¥20 ML307A在使用AT命令连接EMQX平台的MQTT时被拒绝
  • ¥20 腾讯企业邮箱邮件可以恢复么
  • ¥15 有人知道怎么将自己的迁移策略布到edgecloudsim上使用吗?
  • ¥15 错误 LNK2001 无法解析的外部符号
  • ¥50 安装pyaudiokits失败
  • ¥15 计组这些题应该咋做呀
  • ¥60 更换迈创SOL6M4AE卡的时候,驱动要重新装才能使用,怎么解决?
  • ¥15 让node服务器有自动加载文件的功能