单链表：删除单链表尾结点

一、单链表结构定义

typedef int linkType;			///< 定义链表结点数据域数据类型

/// @brief  链表结点定义
typedef struct t_linkNode
{
    struct t_linkNode* pnext;  ///< 结点指针域
    linkType data;             ///< 结点数据域
}myLNode;

/// @brief 链表结构定义
typedef struct t_linkList
{
    myLNode* phead;   //< 链表头结点
}myLinkList;

二、尾删法

/// @brief 删除链表尾结点，即尾删法
/// @param plist 链表指针
/// @return 返回是否删除成功标志
/// @retval ERROR(0)：链表不存在或链表为空，不可操作
/// @retval OK(1)：删除成功
status xxx_pop_back(myLinkList* plist)
{
    if (plist == NULL)
    {
        return ERROR;
    }
    return xxx_pop_back_(plist->phead);
}
status xxx_pop_back_(myLNode* phead)
{
    if (phead == NULL || phead->pnext == NULL)
    {
        return ERROR;
    }
    myLNode* ptail = phead;
    myLNode* pre = NULL;
    /// 循环让ptail最终指向尾结点,pre指向尾结点前驱
    while (ptail->pnext != NULL)
    {
        pre = ptail;
        ptail = ptail->pnext;
    }
    pre->pnext = NULL;
    free(ptail);
    ptail = NULL;
    return OK;
}