feat: added configuration and USE_SLIST

hdrs/libft.h

@@ -1,7 +1,14 @@
 #ifndef LIBFT_H
-# define LIBFT_H
-
-# include <stdlib.h>
+#define LIBFT_H
+#include <stdlib.h>
+#if DEBUG
+#include <stdio.h>
+#define DEBUG_PRINT(fmt, ...) \
+    fprintf(stderr, "[DEBUG] %s:%d:%s(): " fmt "\n", \
+            __FILE__, __LINE__, __func__, ##__VA_ARGS__)
+#else
+#define DEBUG_PRINT(fmt, ...) ((void)0)
+#endif
 
 void *ft_realloc(void *ptr, size_t old_size, size_t new_size);
 
@@ -50,6 +57,7 @@ typedef struct s_string
 } t_string;
 
 /* Single Linked List */
+#if USE_SLIST
 typedef struct s_slist
 {
     void *data;
@@ -71,6 +79,7 @@ t_slist *ft_slist_find(t_slist *lst, void *data, int (*cmp)(void *, void *));
 int ft_slist_insert(t_slist **lst, t_slist *node, int index);
 t_slist *ft_slist_get(t_slist *lst, int index);
 
+#endif 
 /* Vector */
 typedef struct s_vec
 {