在C ++中,如果我有以下形式的二进制搜索树(BST)
Struct node{
node leftChild;
node rightChild;
int data;}
访问leftChild数据是否合法:
foo (node head)
{
std::cout << head.leftChild.data;
}
此外,有时我看到链接列表节点为子节点使用*节点,有时他们只使用节点。何时/为什么要使用其中之一。很抱歉字符串问题很好奇。
答案 0 :(得分:3)
不,因为你不能有这样的结构。它将是无限大的(node
有两个子node
,每个都有两个子node
s,等等。这正是人们在制作具有相同类型子节点的节点时会使用指针的原因。
例如,不如何执行此操作:
/* This is a problem because of the recursive nature of the structure. leftChild also
contains a leftChild itself, which also contains a leftChild, etc. forever. */
struct node
{
node leftChild; // how big is leftChild? infinitely large!
node rightChild; // how big is rightChild? infinitely large!
int data;
}
以正确方式执行此操作:
/* This is not a problem because the size of a pointer is always 4 bytes (assuming 32-
bit system). You can allocate room for the child nodes without recursively requiring an
infinite amount of memory. */
struct node
{
node* leftChild; // how big is leftChild? 4 bytes (assuming 32-bit system)
node* rightChild; // how big is rightChild? 4 bytes (assuming 32-bit system)
int data;
}
一旦你以正确的方式做到这一点,完全合法的说法是:
void foo(node head)
{
std::cout << head.leftChild->data; // assuming leftChild points to a valid object!
}