Update sk1/Makefile

sk1/Makefile

@@ -1,8 +1,16 @@
-all: program
+CC = gcc
+CFLAGS = -Wall -Wextra -std=c99
 
-program: compressor.c main.c
-	gcc	compressor.c	main.c	-o
-program
+all: compressor
+
+compressor: main.o compressor.o
+  $(CC) $(CFLAGS) -o compressor main.o compressor.o
+
+main.o: main.c compressor.h
+  $(CC) $(CFLAGS) -c main.c
+
+compressor.o: compressor.c compressor.h
+  $(CC) $(CFLAGS) -c compressor.c
 
 clean:
-	rm compressor
+  rm -f *.o compressor