train2

cv5/a_train.c

@@ -38,8 +38,9 @@ void cancel_train(struct car* first) {
         exit(0);
     }
     if(first->next == NULL){
-        free(first);
-        first = NULL;
+        struct car *this = first;
+        first = fitst->next;
+        free(this);
         exit(0);
     }
     cancel_train(first->next);