我当时在使用mysql数据库，不幸的是我安装了mariadb，当我想返回mysql时，出现了一个错误，我删除了mariadb并尝试用这个命令安装mysql

sudo apt-get install mysql-server

但我有个错误

Reading package lists... Done
 Building dependency tree
 Reading state information... Done
 mysql-server is already the newest version (5.7.22-0ubuntu0.16.04.1).
   0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
     2 not fully installed or removed.
  After this operation, 0 B of additional disk space will be used.
  Do you want to continue? [Y/n] y
  Setting up mysql-server-5.7 (5.7.22-0ubuntu0.16.04.1) ...
update-alternatives: error: alternative path /etc/mysql/mysql.cnf doesn't 
exist
 dpkg: error processing package mysql-server-5.7 (--configure):
 subprocess installed post-installation script returned error exit status 2
 dpkg: dependency problems prevent configuration of mysql-server:
  mysql-server depends on mysql-server-5.7; however:
 Package mysql-server-5.7 is not configured yet.

 dpkg: error processing package mysql-server (--configure):
 dependency problems - leaving unconfigured
   No apport report written because the error message indicates its a 
  followup error from a previous failure.
                      Errors were encountered while processing:
mysql-server-5.7
   mysql-server
   E: Sub-process /usr/bin/dpkg returned an error code (1)

我不能重新安装mysql，我能做什么，我寻找解决方案，但没有结果