我试图实现一个二叉搜索树的目的是(重新)学习C.问题是,这current = new;
不工作,因为tree.root仍然是一个空指针之后增加两个节点。那有什么问题?二叉搜索树指针问题
#include <stdlib.h>
#include <stdio.h>
typedef struct BinaryNode {
int key;
double value;
struct BinaryNode *left;
struct BinaryNode *right;
} BinaryNode;
typedef struct BinaryTree {
struct BinaryNode *root;
} BinaryTree;
static void binary_tree_insert_recursive(BinaryNode *current, BinaryNode *new) {
if (current == NULL || current->key == new->key) {
current = new;
} else if (current->key > new->key) {
binary_tree_insert_recursive(current->left, new);
} else if (current->key < new->key) {
binary_tree_insert_recursive(current->right, new);
}
}
void binary_tree_insert(BinaryTree *tree, int key, double value) {
BinaryNode *new = (BinaryNode *) malloc(sizeof(BinaryNode));
new->key = key;
new->value = value;
binary_tree_insert_recursive(tree->root, new);
}
int main(void) {
BinaryTree tree;
binary_tree_insert(&tree, 5, 123);
binary_tree_insert(&tree, 10, 123);
printf("%p\n", tree.root);
return 0;
}
谢谢!
hm,所以我需要一个双指针。谢谢! – 2011-06-14 19:56:59
@ahojnnes:对于您创建的每个节点,您可能还需要考虑将“左”和“右”指针初始化为NULL。另外,不要将变量命名为“新”,这是令人困惑的。 – Andrei 2011-06-14 20:00:38
@Andrei:默认情况下是不是用空指针初始化的? – 2011-06-14 20:04:57