Binary tree implementation in c++

btree.cpp

#include <iostream>

using namespace std;


struct node{
	int value;
	node *left;
	node *right;
};

class btree{
public:
	btree();
	~btree();

	void insert(int key);
	node *search(int key);
	void destroy_tree();
	void inorder_print();
	void postorder_print();
	void preorder_print();

private:
	void destroy_tree(node *leaf);
	void insert(int key, node *leaf);
	node *search(int key, node *leaf);
	void inorder_print(node *leaf);
	void postorder_print(node *leaf);
	void preorder_print(node *leaf);

	node *root;
};


btree::btree(){
	root = NULL;
}

btree::~btree(){
	destroy_tree();
}

void btree::destroy_tree(node *leaf){
	if(leaf != NULL){
		destroy_tree(leaf->left);
		destroy_tree(leaf->right);
		delete leaf;
	}
}

void btree::insert(int key, node *leaf){

	if(key < leaf->value){
		if(leaf->left != NULL){
			insert(key, leaf->left);
		}else{
			leaf->left = new node;
			leaf->left->value = key;
			leaf->left->left = NULL;
			leaf->left->right = NULL;
		}
	}else if(key >= leaf->value){
		if(leaf->right != NULL){
			insert(key, leaf->right);
		}else{
			leaf->right = new node;
			leaf->right->value = key;
			leaf->right->right = NULL;
			leaf->right->left = NULL;
		}
	}

}

void btree::insert(int key){
	if(root != NULL){
		insert(key, root);
	}else{
		root = new node;
		root->value = key;
		root->left = NULL;
		root->right = NULL;
	}
}

node *btree::search(int key, node *leaf){
	if(leaf != NULL){
		if(key == leaf->value){
			return leaf;
		}
		if(key < leaf->value){
			return search(key, leaf->left);
		}else{
			return search(key, leaf->right);
		}
	}else{
		return NULL;
	}
}

node *btree::search(int key){
	return search(key, root);
}

void btree::destroy_tree(){
	destroy_tree(root);
}

void btree::inorder_print(){
	inorder_print(root);
	cout << "\n";
}

void btree::inorder_print(node *leaf){
	if(leaf != NULL){
		inorder_print(leaf->left);
		cout << leaf->value << ",";
		inorder_print(leaf->right);
	}
}

void btree::postorder_print(){
	postorder_print(root);
	cout << "\n";
}

void btree::postorder_print(node *leaf){
	if(leaf != NULL){
		inorder_print(leaf->left);
		inorder_print(leaf->right);
		cout << leaf->value << ",";
	}
}

void btree::preorder_print(){
	preorder_print(root);
	cout << "\n";
}

void btree::preorder_print(node *leaf){
	if(leaf != NULL){
		cout << leaf->value << ",";
		inorder_print(leaf->left);
		inorder_print(leaf->right);
	}
}

int main(){

	//btree tree;
	btree *tree = new btree();

	tree->insert(10);
	tree->insert(6);
	tree->insert(14);
	tree->insert(5);
	tree->insert(8);
	tree->insert(11);
	tree->insert(18);

	tree->preorder_print();
	tree->inorder_print();
	tree->postorder_print();

	delete tree;

}

good work .its really helpful.

it is a binary search tree actually,, not binary tree. becoz in a binary tree there is n need to comapre a key while insertion.

you have mistakes in "print" functions, you use always inorder traversal, but you have to use recursion in that function.

If you can correct that, please take the chance and help me as well.

…

On Fri, Nov 6, 2020, 5:30 PM He1ler ***@***.***> wrote: ***@***.**** commented on this gist. ------------------------------ you have mistakes in "print" functions, you use always inorder traversal, but you have to use recursion in that function. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <https://gist.github.com/def6a6915e4abd66e922#gistcomment-3518395>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AN226LTEY7J3FLTX7NINQJ3SOPT5RANCNFSM4ITL37NA> .

In this function:
void btree::inorder_print(node leaf){
if(leaf != NULL){
inorder_print(leaf->left);
cout << leaf->value << ",";
inorder_print(leaf->right);
}
}
void btree::postorder_print(node leaf){
if(leaf != NULL){
inorder_print(leaf->left);
inorder_print(leaf->right);
cout << leaf->value << ",";
}
}
void btree::preorder_print(node leaf){
if(leaf != NULL){
cout << leaf->value << ",";
inorder_print(leaf->left);
inorder_print(leaf->right);
}
} You use always inorder_print, but you should use themselfs, like this :
void inorder_print(Node leaf)
{
if (leaf != NULL)
{
inorder_print(leaf->left);
cout << leaf->data << ", ";
inorder_print(leaf->right);
}
}
void postorder_print(Node leaf)
{
if (leaf != NULL)
{
postorder_print(leaf->left);
postorder_print(leaf->right);
cout << leaf->data << ", ";
}
}
void preorder_print(Node leaf)
{
if (leaf != NULL)
{
cout << leaf->data << ", ";
preorder_print(leaf->left);
preorder_print(leaf->right);
}
}
This function will order rules of tree traversals. Am I right?

why you didn't used search function??
Why did u even made them if u didn't wanted to use it??

Aise hi sexy lag raha tha!!!

Man there is a big mistake in your code. Here:
void btree::preorder_print(node *leaf){
if(leaf != NULL){
cout << leaf->value << ",";
inorder_print(leaf->left);
inorder_print(leaf->right);
}
}

You use "inorder_print" inside "preorder_print". Rightly:
void btree::preorder_print(node *leaf){
if(leaf != NULL){
cout << leaf->value << ",";
preorder_print(leaf->left);
preorder_print(leaf->right);
}
}

The same within "postorder_print". Correct please.

Man there is a big mistake in your code. Here: void btree::preorder_print(node *leaf){ if(leaf != NULL){ cout << leaf->value << ","; inorder_print(leaf->left); inorder_print(leaf->right); } }

You use "inorder_print" inside "preorder_print". Rightly: void btree::preorder_print(node *leaf){ if(leaf != NULL){ cout << leaf->value << ","; preorder_print(leaf->left); preorder_print(leaf->right); } }

The same within "postorder_print". Correct please.

Please use markdown, especially for code blocks. Makes it easier to read.

Github basic writing and formatting

the code is very clean, I watched a video about binary trees and immediately found a clear and understandable implementation