C ++ implements a binary search tree

Implement the data structure of the Binary Search Tree and record it as follows:

# Include
 
  
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 <"analyze Binary Search Tree:" <
  
   
Left); Destory (node-> right); cout <
   
    
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; else pre-> right = p ;}} void SearchTree :: predisplay () {Preorder (root);} void SearchTree: Preorder (TreeNode * root) {if (root) {cout <
    
     
Val <"; Preorder (root-> left); Preorder (root-> right) ;}} void SearchTree: Indisplay () {Inorder (root );} void SearchTree: Inorder (TreeNode * root) {if (root) {Inorder (root-> left); cout <
     
      
Val <"; Inorder (root-> right) ;}} void SearchTree: Postdisplay () {Postorder (root) ;} void SearchTree: Postorder (TreeNode * root) {if (root) {Postorder (root-> left); Postorder (root-> right); cout <
      
        Val <"" ;}} int main () {SearchTree t; int a [] = }; int n = sizeof (a)/sizeof (a [0]); cout <"construct a binary search tree:" <