示例#1
0
BTNode* BTree_search(const BTree tree, int key, int* pos)
{
	if (!tree) {
		return NULL;
	}

	int i = 0;

	while (i < tree->keynum && key > tree->key[i]) {
		++i;
	}

	// Find the key.
	if (i < tree->keynum && tree->key[i] == key) {
		if (pos) {
			*pos = i;
		}

		return tree;
	}

	// tree 为叶子节点,找不到 key,查找失败返回
	if (tree->isLeaf) {
		return NULL;
	}

	// 节点内查找失败,但 tree->key[i - 1]< key < tree->key[i],
	// 下一个查找的结点应为 child[i]

	// 从磁盘读取第 i 个孩子的数据
	disk_read(&tree->child[i]);

	// 递归地继续查找于树 tree->child[i]
	return BTree_search(tree->child[i], key, pos);
}
示例#2
0
//==================================================================
//					测试 B 树
//==================================================================
void test_BTree_search(BTree tree, int key)
{
	int pos = -1;
	BTNode*	node = BTree_search(tree, key, &pos);
	if (node) {
		printf("在%s节点(包含 %d 个关键字)中找到关键字 %c,其索引为 %d\n",
			node->isLeaf ? "叶子" : "非叶子",
			node->keynum, key, pos);
	}
	else {
		printf("在树中找不到关键字 %c\n", key);
	}
}