Some refactoring.

queue.c

@@ -0,0 +1,37 @@
+#include "queue.h"
+
+void qinit(queue *item)
+{
+    item->first = NULL;
+    item->last = NULL;
+}
+
+void qput(queue *item, particle data)
+{
+    if(!item->first) {
+        item->first = malloc(sizeof(struct node));
+        item->last = item->first;
+    } else {
+        item->last->next = malloc(sizeof(struct node));
+        item->last = item->last->next;
+    }
+    item->last->data = data;
+    item->last->next = NULL;
+}
+
+void qget(queue *item, particle *data)
+{
+    if(data)
+        *data = item->first->data;
+
+    struct node *tmp = item->first;
+    item->first = item->first->next;
+    if(!item->first)
+        item->last = NULL;
+    free(tmp);
+}
+
+int qempty(queue *item)
+{
+    return !item->first;
+}