二叉排序树的C++实现

二叉排序树的主要操作有插入、创建、查找、删除。用C++实现了一下

#include <iostream>
using namespace std;
#include <stack>

class Node
{
int data;
Node *lchild;
Node *rchild;
public:
Node (int val, Node *left = NULL, Node *right = NULL)
{
data = val;
lchild = left;
rchild = right;
}
int Data()
{
return data;

}
friend class Binary_sort_Tree;
};

class Binary_sort_Tree
{
private:
Node *root;
public:
Binary_sort_Tree()
{
root = NULL;
}
~Binary_sort_Tree(){};
void Insert(Node *&temp, int a);
void Creat(int *a, int n);
Node* search(Node *cur, int val);
Node* Search(int val)
{
return search(root, val);
}
bool DeleteBST(Node *&cur, int val);
bool Delete(Node *&cur);
void InOrder();

Node* Root()
{
return root;
}
};

void Binary_sort_Tree::Insert(Node *&temp, int a)
{
if (temp == NULL)
temp = new Node(a);
else if (temp->data >= a)
Insert(temp->lchild, a);
else
Insert(temp->rchild, a);
}
void Binary_sort_Tree::Creat(int *a, int n)
{
for (int i = 0; i < n; i++)
Insert(root, a[i]);
}
void Binary_sort_Tree::InOrder()
{
Node *cur = root;
if (cur == NULL)
return;
stack<Node *> s;
while (cur || !s.empty())
{
while (cur)
{
s.push(cur);
cur = cur->lchild;
}
Node *top = s.top();
s.pop();
cout<<top->data<<" ";
cur = top->rchild;
}
cout<<endl;
}
Node* Binary_sort_Tree::search(Node *cur, int val)
{
Node *temp = cur;
Node *ret = NULL;
if (temp == NULL)
return ret;
if (temp->data == val)
ret = temp;
else if (temp->data < val)
{
ret = search(temp->lchild, val);
}
else
{
ret = search(temp->rchild, val);
}
return ret;
}
bool Binary_sort_Tree::DeleteBST(Node *&cur, int val)
{
if (cur == NULL)
{
return false;
}
if (cur->data == val)
{
return Delete(cur);
}
else if (cur->data > val)
{
return DeleteBST(cur->lchild, val);
}
else
{
return DeleteBST(cur->rchild, val);
}
}
bool Binary_sort_Tree::Delete(Node *&cur)
{
if (cur->rchild == NULL)
{
Node *temp = cur;
cur = cur->lchild;
delete temp;
}
else if (cur->lchild == NULL)
{
Node *temp = cur;
cur = cur->rchild;
delete temp;
}
else
{//左右子树均不为空
Node *temp = cur;
Node *p = cur->lchild;
while (p->rchild)
{
temp = p;
p = p->rchild;
}
cur->data = p->data;
if (cur != temp)
temp->rchild = p->lchild;
else
temp->lchild = p->rchild;
delete p;
}
return true;
}

void main()
{
Binary_sort_Tree tree;
int a[] = {62,88,58,47,35,73,51,99,37,93};
tree.Creat(a, 10);
tree.InOrder();
Node *temp = tree.Root();
bool Delete = tree.DeleteBST(temp,58);
if (Delete == false)
cout<<"NULL"<<endl;
else
tree.InOrder();
}
主要的操作难点在于删除操作，删除也是先查找才能删除，查找部分采用递归，删除的话分三种情况，即左子树为空，右子树为空，或者左右子树均不为空。需要注意的是，在前两种情况删除结点的时候，参数需要采用引用，不然删除结点的时候会出现问题。