Insertion in binary search tree using recursion in c++
C++ program for Insertion in binary search tree using recursion. Here more information.
// Include header file
#include <iostream>
using namespace std;
// C++ program for
// Insertion in binary search tree by using recursion
class TreeNode
{
public: int data;
TreeNode *left;
TreeNode *right;
TreeNode(int data)
{
this->data = data;
this->left = nullptr;
this->right = nullptr;
}
};
class BinarySearchTree
{
public: TreeNode *root;
BinarySearchTree()
{
this->root = nullptr;
}
// Insert a node element
TreeNode *addNode(TreeNode *node, int data)
{
if (node != nullptr)
{
if (node->data >= data)
{
// When new element is smaller or
// equal to current node
node->left = this->addNode(node->left, data);
}
else
{
// When new element is higher to current node
node->right = this->addNode(node->right, data);
}
// important to manage root node
return node;
}
else
{
return new TreeNode(data);
}
}
// Display preorder
void preorder(TreeNode *node)
{
if (node != nullptr)
{
// Display node value
cout << " " << node->data;
// Visit to left subtree
this->preorder(node->left);
// Visit to right subtree
this->preorder(node->right);
}
}
void inorder(TreeNode *node)
{
if (node != nullptr)
{
// Visit to left subtree
this->inorder(node->left);
// Display node value
cout << " " << node->data;
// Visit to right subtree
this->inorder(node->right);
}
}
void postorder(TreeNode *node)
{
if (node != nullptr)
{
// Visit to left subtree
this->postorder(node->left);
// Visit to right subtree
this->postorder(node->right);
// Display node value
cout << " " << node->data;
}
}
};
int main()
{
BinarySearchTree *tree = new BinarySearchTree();
/*
10
/ \
/ \
4 15
/ \ /
3 5 12
-------------
Build binary search tree
*/
tree->root = tree->addNode(tree->root, 10);
tree->addNode(tree->root, 4);
tree->addNode(tree->root, 3);
tree->addNode(tree->root, 5);
tree->addNode(tree->root, 15);
tree->addNode(tree->root, 12);
// Display tree nodes
cout << "Preorder " << endl;
tree->preorder(tree->root);
cout << "\nInorder " << endl;
tree->inorder(tree->root);
cout << "\nPostorder " << endl;
tree->postorder(tree->root);
return 0;
}
Output
Preorder
10 4 3 5 15 12
Inorder
3 4 5 10 12 15
Postorder
3 5 4 12 15 10
Please share your knowledge to improve code and content standard. Also submit your doubts, and test case. We improve by your feedback. We will try to resolve your query as soon as possible.
New Comment