I downloaded the Makefile from the same site [1]. I changed CC to gcc (not sure if necessary) then just ran "make jarijyrki". The relevant build command makes it clear why your compile command fails.

   	${CC} ${X11CCFLAGS} ${CFLAGS} -DNeedFunctionPrototypes \
   	    -DU=40 -DT=98 '-Dz=(T+1)*U*U' -DQ=80 -DS=20 -DN=10 -DB=5 -DG=23 \
   	    -Dp=7 '-DM=((p+1)*Q)+S' '-DH=(G*S)+S+S' -DC=XK_Up -DL=XK_Down \
   	    -DO=XK_Left -DV=XK_Right -DR=XK_Escape -D_=XK_BackSpace \
   	    $? -o $@ ${X11LDFLAGS} -lX11

I guess there was a limitation on the length on the compilation command too and the winner made use of it fully. You have to run it as "./jarijyrki < sheet1.info > myedits.info", sheet1.info is in the same site[2].

[1] http://www.ioccc.org/2000/Makefile [2] http://www.ioccc.org/2000/sheet1.info