c++实现二叉搜索树

自己实现了一下二叉搜索树的数据结构。记录一下：

#include <iostream>using namespace std;struct TreeNode{int val;TreeNode *left;TreeNode *right;TreeNode(int value) { val=value; left=NULL; right=NULL; }
};class SearchTree{public:SearchTree();~SearchTree();void Destory(TreeNode *);void Insertnode(int);void Preorder(TreeNode *);void Inorder(TreeNode *);void Postorder(TreeNode *);void Predisplay();void Indisplay();void Postdisplay();
private:TreeNode *root;};SearchTree::SearchTree()
{root=NULL;
}SearchTree::~SearchTree()
{cout<<"析构二叉搜索树："<<endl;Destory(root);
}void SearchTree::Destory(TreeNode *node)
{if(node!=NULL){Destory(node->left);Destory(node->right);cout<<node->val<<" ";delete node;}
}void SearchTree::Insertnode(int value)
{if(root==NULL)root=new TreeNode(value);else{TreeNode *p,*pre;pre=p=root;while(p){if(p->val==value)return;else if(p->val>value){pre=p;p=p->left;}else{pre=p;p=p->right;}}p=new TreeNode(value);if(pre->val>value)pre->left=p;elsepre->right=p;}
}void SearchTree::Predisplay()
{Preorder(root);
}void SearchTree::Preorder(TreeNode *root)
{if(root){cout<<root->val<<" ";Preorder(root->left);Preorder(root->right);}
}void SearchTree::Indisplay()
{Inorder(root);
}void SearchTree::Inorder(TreeNode *root)
{if(root){Inorder(root->left);cout<<root->val<<" ";Inorder(root->right);}
}void SearchTree::Postdisplay()
{Postorder(root);
}void SearchTree::Postorder(TreeNode *root)
{if(root){Postorder(root->left);Postorder(root->right);cout<<root->val<<" ";}
}int main()
{SearchTree t;int a[]={7,4,2,3,15,35,6,45,55,20,1,14};int n=sizeof(a)/sizeof(a[0]);cout<<"构造二叉搜索树："<<endl;for(int i=0;i<n;++i){cout<<a[i]<<" ";t.Insertnode(a[i]);}cout<<endl<<"先序遍历序列: "<<endl;t.Predisplay();cout<<endl<<"中序遍历序列: "<<endl;t.Indisplay();cout<<endl<<"后序遍历序列: "<<endl;t.Postdisplay();cout<<endl;return 0;
}