added code

.gitignore

@@ -0,0 +1,2 @@
+.DS_Store
+.vscode

makefile

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+CC=gcc
+CFLAGS=-Wall -Wextra -Wno-implicit-fallthrough -std=gnu17 -fPIC -O2 -g
+LDFLAGS=-shared -Wl,--wrap=malloc -Wl,--wrap=calloc -Wl,--wrap=realloc -Wl,--wrap=reallocarray -Wl,--wrap=free -Wl,--wrap=strdup -Wl,--wrap=strndup
+
+all: libseq.so 
+str.o: str.c str.h
+	@$(CC) $(CFLAGS) -c str.c
+seq.o: seq.c seq.h str.h
+	@$(CC) $(CFLAGS) -c seq.c
+seq_example.o: seq_example.c seq.h memory_tests.h
+	@$(CC) $(CFLAGS) -c seq_example.c
+memory_tests.o: memory_tests.h memory_tests.c 
+	@$(CC) $(CFLAGS) -c memory_tests.c 
+example: libseq.so seq_example.o 
+	@$(CC) $(CFLAGS) -o example -g seq_example.o -L. -lseq
+libseq.so: seq.o str.o memory_tests.o 
+	@$(CC) $(CFLAGS) $(LDFLAGS) -o libseq.so $^
+clean: 
+	@rm -f *.o test libseq.so