定义一个双向链表，并且设计一个函数，查找并且插入元素，保持链表有序排列
STATUS insert_data_into_double_link(DOUBLE_LINK_NODE** ppDLinkNode, int data)
{
DOUBLE_LINK_NODE* pNode;
DOUBLE_LINK_NODE* pIndex;
if(NULL == ppDLinkNode)
return FALSE;
if(NULL == *ppDLinkNode){
pNode = create_double_link_node(data);
assert(NULL != pNode);
*ppDLinkNode = pNode;
(*ppDLinkNode)->prev = (*ppDLinkNode)->next = NULL;
return TRUE;
}
if(NULL != find_data_in_double_link(*ppDLinkNode, data))
return FALSE;
pNode = create_double_link_node(data);
assert(NULL != pNode);
pIndex = *ppDLinkNode;
while(NULL != pIndex->next)
pIndex = pIndex->next;
pNode->prev = pIndex;
pNode->next = pIndex->next;
pIndex->next = pNode;
return TRUE;
}