链表的源代码，分为带头节点的链表，不带头节点的链表。-Chain source code into the lead in the linked list node, the node does not take the lead List.

打字训练系统源码。采用链表操作实现，所有功能均已测试完成。保证不是坑人的操作。-Typing training system source code. Using chain operations to achieve, all functions have been tested complete. Ensure the operation is not deceptive.