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binary search tree proble. help !!

hdyh (15)
This code is about to insert number, i want to change it to search a name or alphabet according to inorder,postorder and preorder. Help me to change some syntax that i call insert name or alphabet in the code.

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

class treeNode
{
	public:
		treeNode*left;
		treeNode*right;
		int data;
};

class BinarySearchTree
{
	private:
		treeNode*root;
		public:
			BinarySearchTree() 
			{root=NULL;
			}
			bool isEmpty () const {
			return root ==NULL;}
			void printInorder();
			void Inorder (treeNode*);
			void printPreorder();
			void Preorder (treeNode*);
			void printPostorder();
			void Postorder (treeNode*);
			void insert (int);
		
};

int main()
{
	BinarySearchTree myTree;
	int ch, inItem;
	do
	{
		cout<<endl<<endl;
		cout<<"Binary Search Tree Operations" <<endl;
		cout<<"--------------------------------------"<<endl;
		cout<<"1. Insertion/Creation "<<endl;
		cout<<"2. Inorder Traversal "<<endl;
		cout<<"3. Preorder Traversal "<<endl;
		cout<<"4. Postorder Travesal "<<endl;
		cout<<"5. Exit "<<endl;
		cout<<"Enter Your choice :";
		cin>>ch;
		system ("cls");
		
		switch (ch)
		{
			case 1: cout<<" enter number to be inserted :";
			cin >>inItem;
			myTree.insert (inItem);
			break;
			case 2: cout<<endl;
			cout<<" Inorder Traversal "<<endl;
			myTree.printInorder();
			break;
			case 3: cout<<endl;
			cout<<" Preorder travesal "<<endl;
			myTree.printPreorder();
			break;
			case 4: cout<<endl;
			cout<<" Postorder Travesal "<<endl;
			myTree.printPostorder ();
			break;
		}
		
		
		
	}while (ch!=5);
}

void BinarySearchTree::insert(int item) //insert
{
	treeNode*temp=new treeNode;
	treeNode*parent;
	temp->data=item;
	temp->left=NULL;
	temp->right=NULL;
	parent=NULL;
	//is this new tree ?
	
	if(isEmpty())root=temp;
	else
	{
		//note:all insertions are as leafnode
		treeNode*curr;
		curr=root;
		//find the node parent
		while(curr)
		{
			parent=curr;
			if(temp->data > curr->data) curr=curr->right;
			else curr= curr->left;
			
		}
		
		if(temp->data<parent->data)
		parent->left=temp;
		else
		parent->right=temp;
	}	
}

void BinarySearchTree::printInorder() //recursive
{
	Inorder(root);
}

void BinarySearchTree::Inorder(treeNode*p)
{
	if(p!=NULL)
	{
		if(p->left) Inorder (p->left); //CALL THE NODE
		cout<<" " <<p->data<<" ";
		if(p->right) Inorder (p->right);
	}
	else return;	
}

void BinarySearchTree::printPreorder() //recursive
{
	Preorder(root);
}

void BinarySearchTree::Preorder(treeNode*p)
{
	if(p!=NULL)
	{
		cout<<" " <<p->data<<" ";
		if(p->left) Preorder (p->left); //CALL THE NODE
		if(p->right) Preorder (p->right);
	}
	else return;	
}

void BinarySearchTree::printPostorder() //recursive
{
	Postorder(root);
}

void BinarySearchTree::Postorder(treeNode*p)
{
	if(p!=NULL)
	{
		if(p->left) Postorder (p->left); //CALL THE NODE
		if(p->right) Postorder (p->right);                                    
		cout<<" " <<p->data<<" ";
		
	}
	else return;	
}
Last edited on
dhayden (5795)
Change treeNode::data to a string. Then search the code for "data" and examine each usage of the variable to see what (if anything) needs to change. This may sound a little tedious but trust me, it 's a good way to catch all the cases.
hdyh (15)
sorry dhayden, I not understand well. can you explain and guide me
dhayden (5795)
As I understand it, you need to change the tree to contain a name instead of a number. So you need to change treeNode's data member to a string:
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class treeNode
{
	public:
		treeNode*left;
		treeNode*right;
		std::string data;
};


Then you should go through the code, looking for "data" and seeing what (if anything) needs to change because it's now a string instead of an int.
hdyh (15)
I have tried to change the code, but its not working. can you please help me :(
dhayden (5795)
Please post your modified code
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