Added clear and add

C-RK/C-RK-Week2/llist.c

@@ -20,20 +20,23 @@ int add(int data)
 
 	if(NULL ==  pn)
 	{
-		printf("Out of memory ...");
+		printf("Out of memory ...\n");
 	}
 	else
 	{
 		if(NULL == pHead)
 		{
 			pn->data = data;
+			pn->previous = NULL;
 			pn->next = NULL;
 			pHead = pn;
 		}
 		else
 		{
+			pHead->next = pn;
 			pn->data = data;
-			pn->next = pHead;
+			pn->previous = pHead;
+			pn->next = NULL;
 			pHead = pn;
 		}
 	}
@@ -46,10 +49,34 @@ void show()
 	struct node *p = pHead;
 	int nr = 0;
 	
-	for( ; NULL !=  p->next ; p = p->next )
+	if (NULL == pHead)
 	{
-		printf("node nr: %d heeft data [%d]\n",nr++,p->data);
+		printf("De lijst is leeg\n");
+	}
+	else
+	{
+		for (; NULL != p->previous; p = p->previous)
+		{
+			printf("node nr: %d heeft data [%d]\n", nr++, p->data);
+		}
 	}
 }
 
+void clear()
+{
+	struct node *p = pHead;
+	struct node *prev = NULL;
+
+	for (; NULL != p->previous;)
+	{
+		prev = p->previous;
+		free(p);
+		p = prev;
+	}
+
+	pHead = NULL;
+
+	printf("De gehele lijst in gecleared!\n");
+}
+
 

C-RK/C-RK-Week2/llist.h

@@ -5,6 +5,7 @@ struct node
 {
 	int data;
 	struct node *next;
+	struct node *previous;
 };
 
 void init();

C-RK/C-RK-Week2/main.c

@@ -5,13 +5,27 @@ int main()
 {
 	int idx;	
 
+	printf("Running init...\n");
+
 	init();
 
+	printf("Adding data...\n");
+
 	for(idx = 0; idx < 10; idx++)
 	{
 		add(idx);
 	}		
+
+	printf("Showing data...\n");
 	show();
 
+	printf("Clearing data...\n");
+	clear();
+
+	printf("Showing data...\n");
+	show();
+
+	printf("Done\n");
+
 	return 1;
 }