链接列表不能连接节点。

I created a list and i checked through the countnodes function if the nodes are connected. The countnodes functions gave me the right answer and i thought that everything it's okay. But , when i tried to delete a node i realised that the nodes are not even connected to the head. I know that the problem is in the insert function because the cur always gives something different from zero and the insert function returns zero and the nodes never connect to each other.I created a list and i checked through the coun