Program | DEL.C, DEL.CPP, DEL.PAS |
It is required to find out whether it is possible to delete given files from
MS-DOS directory executing the DEL command of MS-DOS operation system only once.
There are no nested subdirectories.
A note
DEL command has the following format: DEL wildcard
The actual wildcard as well as a full file name can be made up either of a name
containing 1 up to 8 characters or of a name and extension, containing up to
3 characters. The point character "." separates the extension from
the file name. The extension can be empty and this is equivalent to a name without
any extension (in this case a wildcard ends with a point). In a wildcard the
characters "?" and "*" can be used. A question mark substitutes
exactly one character of the full file name excluding a point, an asterisk -
any sequence of characters (containing no points) even empty one. An asterisk
can appear only at the last position of the name and the extension.
MS-DOS system can permit maybe other wildcards but they can not be used in this
task. File names and extensions consist only of Latin capitals and digits.
For each case write to the first line of output data file DEL.OUT the required DEL command (only one proposal) or IMPOSSIBLE if there is no solution. A space should separate "DEL" from wildcard.
Input data file example:
-BP.EXE
-BPC.EXE
+TURBO.EXE
1999
-BP.EXE
+BP.EXM
-BP.EYM
1999
Possible output data file for our example:
DEL ?P*.*
IMPOSSIBLE