BST 的基本操作

插入及建立

void insert(node* &root, int x)
{
    
    
	if(root == NULL)
	{
    
    
		root = newNode(x);
		return;
	}
	if(x == root->data) return;
	else if(x < root->data) insert(root->lchild, x);
		 else insert(root->rchild, x);
}

node* Create(int data[], int n)
{
    
    
	node* root = NULL;
	for(int i = 0; i < n; i++)
	{
    
    
		insert(root, data[i]);
	}
	return root;
}

删除结点

node* findMax(node* root)
{
    
    
	while(root->rchild != NULL)
	{
    
    
		root = root->rchild;
	}
	return root;
}

node* findMin(node* root)
{
    
    
	while(root->lchild != NULL)
	{
    
    
		root = root->lchild;
	}
	return root;
}

void deleteNode(node* &root, int x)
{
    
    
	if(root == NULL) return;
	if(root == x)
	{
    
    
		if(root->lchild == NULL && root->rchild == NULL) root = NULL;
		else if(root->lchild != NULL){
    
    
			node* pre = findMax(root->lchild);
			root->data = pre->data;
			deleteNode(root->lchild, pre->data); 
		} else{
    
    
			node* next = findMin(root->rchild);
			root->data = next->data;
			deleteNode(root->rchild, next->data);
		}
	}
	else if(root->data > x) deleteNode(root->lchild, x);
	     else deleteNode(root->rchild, x);
}

对二叉查找树进行中序遍历，遍历的结果是有序的。