BinarySearchTree-二叉搜索树
二叉查找树（Binary Search Tree）。搜索,插入,删除的复杂度等于树高，O(log(n))。
- 若它的左子树不空，则左子树上所有结点的值均小于它的根结点的值；
- 若它的右子树不空，则右子树上所有结点的值均大于它的根结点的值；
- 它的左、右子树也分别为二叉排序树；
代码实现如下：
/*****BinarySearchTree*****/
//根节点左边的数据比根节点小，右边比根节点大，子树也一样
#include <iostream>
#include <stack>
using namespace std;
class BinarySearchTree
{
private:
int data;
BinarySearchTree *left;
BinarySearchTree *right;
public:
BinarySearchTree(int x): data(x), left(nullptr), right(nullptr) {}
//插入
void Insert(BinarySearchTree *root,int x)
{
if(root->data<x) //根节点的data<x,则插入右子树
{
if(root->right==nullptr)
root->right = new BinarySearchTree(x);
else
Insert(root->right, x);
}
else
{
if(root->left==nullptr)
root->left = new BinarySearchTree(x);
else
Insert(root->left, x);
}
}
//前序遍历
void PreOrder(BinarySearchTree *root)
{
stack<BinarySearchTree *> s;
BinarySearchTree *p = root;
while(p||!s.empty())
{
while(p)
{
visit(p);
s.push(p);
p = p->left;
}
if(!s.empty())
{
p = s.top();
s.pop();
p = p->right;
}
}
}
//中序遍历
void InOrder(BinarySearchTree *root)
{
stack<BinarySearchTree *> s;
BinarySearchTree *p = root;
while(p||!s.empty())
{
while(p)
{
s.push(p);
p=p->left;
}
if(!s.empty())
{
p = s.top();
visit(p);
s.pop();
p = p->right;
}
}
}
//访问数据
void visit(BinarySearchTree *root)
{
cout<<root->data<<" ";
}
};
int main()
{
int data[8]={6,3,5,1,9,10,22,33};
BinarySearchTree *root = new BinarySearchTree(6);
for(int i =1;i<8;i++)
root->Insert(root,data[i]);
cout<<"中序遍历为：";
root->InOrder(root);
cout<<endl;
cout<<"前序遍历为：";
root->PreOrder(root);
return 0;
}