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

2025.02.28/06Ex/main.c

@@ -0,0 +1,68 @@
+#include "solve.h"
+#include "sort.h"
+#include "array.h"
+#include "io_status.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <time.h>
+
+int main(int argc, char *argv[])
+{
+	/* ./a06.out c n p filename */
+	int c, n, p, diff, task = 6;
+	io_status ret;
+	char *name, **a;
+	int (*cmp)(const char *, const char *);
+	int (*f[])(const char *, const char *) = {up_strcmp, down_strcmp, up_len, down_len};
+	int len_f = sizeof(f) / sizeof(f[0]);
+	double t;
+
+	if (!(argc == 5 && sscanf(argv[1], "%d", &c) && sscanf(argv[2], "%d", &n) == 1 && sscanf(argv[3], "%d", &p) == 1 && c >= 1 && c <= len_f))
+	{
+		printf("Usage %s c n p name\n", argv[0]);
+		return 1;
+	}
+	name = argv[4];
+	cmp = f[c-1];
+
+	if (!(a = (char **)malloc(n * sizeof(char *))))
+	{
+		printf("Not enough memory: \n");
+		return 2;
+	}
+	ret = read_array(a, n, name);
+
+	do {
+		switch(ret)
+		{
+			case SUCCESS:
+				continue;
+			case ERROR_OPEN:
+				printf("Cannot open %s\n", name);
+				break;
+			case ERROR_READ:
+				printf("Cannot read %s\n", name);
+				break;
+			case ERROR_MEM:
+				printf("Not enough memory");
+				break;
+		}
+			free(a);
+			return 3;
+	} while (0);
+	
+	print_array(a, n, p);
+	t = clock();
+	t6_solve(a, n, cmp);
+	t = (clock() - t) / CLOCKS_PER_SEC;
+	diff = check(a, n, cmp);
+
+	printf("New array:\n");
+	print_array(a, n, p);
+	printf("%s : Task = %d Diff = %d Elapsed = %.2f\n", argv[0], task, diff, t);
+	
+	free_array(a, n);
+	free(a);
+
+	return 0;
+}