Helper Programs for Topcoder Problems

CS302
James S. Plank
Link last modified: Wed Aug 19 10:24:08 EDT 2015

Here is the code that I use when doing topcoder. I use the "FileEdit" editor, which copies the topcoder problem into a file in a directory that I specify. Poke around the topcoder web pages and you can learn how to do that. For the options -- here's a screen shot of what mine are.

Now, cd into that directory, and do the following:

UNIX> tar xpfv ~jplank/cs302/tchelpers.tar
q
qprocess.c
qpscript.sh
helpers.h
UNIX> gcc -I/home/plank/include -o qprocess qprocess.c /home/plank/lib/LINUX-X86_64/libfdr.a -lm
UNIX>

When you first download a program from Topcoder, type q. For example, suppose I have just downloaded the NoEights program (SRM 355, D2, 550). I type q, and it will say:

UNIX> q
NoEights.cpp
UNIX> q

When I do a long listing, I see that it has created some new files:

UNIX> ls -l
-r-------- 1 plank loci  1049 2011-09-02 11:18 backup-NoEights.cpp
-rw-r--r-- 1 plank loci   865 2011-09-02 11:18 desc-NoEights.cpp.html
-rwxrwxrwx 1 plank loci   938 2011-09-02 11:11 helpers.h
-rw-r--r-- 1 plank loci   937 2011-09-02 11:18 junk-desc-backup.txt
-rw-r--r-- 1 plank loci   870 2011-09-02 11:18 junk.html
-rw-r--r-- 1 plank loci   568 2011-09-02 11:18 main.cpp
-rw-r--r-- 1 plank loci   732 2011-09-02 11:18 NoEights.cpp
-rwxr-xr-x 1 plank loci    69 2011-09-02 11:10 q
-rwxr-xr-x 1 plank loci 23969 2011-09-02 11:14 qprocess
-rwxrwxrwx 1 plank loci  6040 2011-09-02 11:12 qprocess.c
-rwxrwxrwx 1 plank loci   526 2010-09-26 13:34 qpscript.sh
UNIX>

Ignore the junk files. The important files are:

backup-NoEights.cpp: That's the original file that you downloaded. It has been protected 0400 so that you can't mistakenly delete it. You can delete it with rm -f or you can chmod it and delete it.
NoEights.cpp: This is now ready for you to program -- the class definition and skeleton implementation are made for you, and you have a bunch of #includes and #defines ready. If the program uses an integer, string or double vector, then it typedefs IVec, SVec or DVec. It may even do a LLVec.
desc-NoEights.cpp.html: This is html of the description. Unfortunately, if the description has HTML stuff in it already, the formatting doesn't come through correctly. Be forewarned.
main.cpp: This is the driver program that includes NoEights.cpp and has the examples as command line arguments. Just compile with g++ main.cpp. You can add your own test cases too. There have been one or two problems where this doesn't work (usually involving string vectors or the like), so again, be forewarned. However, if I assign you a topcoder problem for which this doesn't work, I'll let you know.

If you call q on a file that you have edited already (let's say you've already worked on the topcoder problem, and you re-download it), it won't work. However, if you have the backup available, what you can do is: Move your intermediate version to another file, copy the backup to its original filename, chmod it to 0644, then call q again. It will complain that it can't write the backup, but that's not a problem. You have your main.cpp, and that's the important thing. Move your intermediate version back and you're ready to go.