Merge pull request wangzheng0822#263 from Devil0F/patch-1

添加注释，方便个人理解

Author: wangzheng0822

c-cpp/06_linkedlist/Dlist/Dlist.h

@@ -7,17 +7,17 @@
  ************************************************************************/
 #include<stdio.h>
 
-typedef struct DlistNode
-{
-struct DlistNode *prev;
-struct DlistNode *next;
-int data;
+typedef struct DlistNode //双向链表中每一个节点
+{ 
+struct DlistNode *prev; //节点前项指针
+struct DlistNode *next; //节点后项指针
+int data; //数据
 }stDlistNode;
 
-typedef struct Dlisthead
+typedef struct Dlisthead //定义链表总体
 {
-int size;
-stDlistNode *head;
-stDlistNode *tail;
+int size; //链表长度
+stDlistNode *head; //头指针
+stDlistNode *tail; //尾部指针
 }stDlistHead;