使用指针删除链表中的节点

Question

我正在尝试编写一种方法，该方法获取链接列表（** pplist）和要删除的项目的地址（* pplaneToDelete）。 这是我写的，程序崩溃了。有帮助吗？

void DeleteAirplane(plane **pplist, plane *pplaneToDelete) {
plane *cur = pplist, *prev = NULL;

if (cur = pplaneToDelete) {

    pplist =cur->next_plane;
    free(cur);
}
while ((cur != pplaneToDelete) && (cur != NULL)) {
    prev = cur;
    cur = cur->next_plane;
}
if (cur != NULL) {
    prev->next_plane = cur->next_plane;
    free(cur);
}
}

修改： 我更改为：

void DeleteAirplane(plane **pplist, plane *pplaneToDelete) {
plane *cur = *pplist, *prev = NULL;

if (cur == pplaneToDelete) {
    *pplist =cur->next_plane;
    free(cur);
    return;
}
while ((cur != pplaneToDelete) && (cur != NULL)) {
    prev = cur;
    cur = cur->next_plane;
}
if (cur != NULL) {
    prev->next_plane = cur->next_plane;
    free(cur);
}
}

有效！ 任何意见？

Answer 1

这里没有什么问题。

1. (cur = pplaneToDelete)是分配而不是比较 因此将其更改为(cur == pplaneToDelete)。

2. pplist是指向指针的指针，因此您需要取消引用它才能获取其持有的指针对象。

   plane *cur = pplist-> plane *cur = *pplist

   pplist =cur->next_plane; ---> *pplist =cur->next_plane;

3. 删除头节点后，您需要return，否则将尝试访问cur指针来调用未定义的行为。

   if (cur == pplaneToDelete) { *pplist =cur->next_plane; free(cur); return; // Node deleted now return. }