refactor(structure): normalize folder names with leading zeros for consistency

- Renamed all folders from format NEx (e.g., 1Ex, 2Ex...) to 0NEx (01Ex, 02Ex, etc.)
- Updated subdirectories and files accordingly
- Removed old main Makefile and tasks (a01.c–a09.c, solve.c, io_status.h), likely obsolete
- Cleaned up deprecated task binaries and configs

2025.02.28/09Ex/array.h

@@ -0,0 +1,15 @@
+#ifndef ARRAY_H
+#define ARRAY_H
+
+#include "io_status.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+io_status read_array(char *a[], int n, const char *name);
+void free_array(char **a, int n);
+void print_array(char **a, int n, int m);
+int check(char **a, int n, int (*cmp)(const char *, const char *));
+
+#endif