Delete leaf nodes with value k in C++ program

In this tutorial, we are going to learn how to delete the leaf nodes from a tree with the given value.

Let's see the steps to solve the problem.

• Write a struct Node for a binary tree.

• Write a function to traverse (inorder, preorder, postorder) through the tree and print all data.

• Initialize the tree by creating nodes with the struct.

• Initialize the x value.

• Write a function to delete the leaf nodes with the given value. It accepts two arguments root node and k value.

  • If the root is a null return.

  • Replace the left node of the root with a new root after deletion.

  • Same with the right node of the root.

  • If the current root node data is equal to k and it is a leaf node, then return a null pointer.

  • Return root node

Example

Let's see the code.

 Live Demo

#include <bits/stdc++.h> using namespace std; struct Node {    int data;    struct Node *left, *right; }; struct Node* newNode(int data) {    struct Node* newNode = new Node;    newNode->data = data;    newNode->left = newNode->right = NULL;    return newNode; } Node* deleteLeafNodes(Node* root, int k) {    if (root == NULL) {       return nullptr;    }    root->left = deleteLeafNodes(root->left, k);    root->right = deleteLeafNodes(root->right, k);    // checking the current node data with k    if (root->data == k && root->left == NULL && root->right == NULL) {       // deleting the node       return nullptr;    }    return root; } void inorder(Node* root) {    if (root == NULL) {       return;    }    inorder(root->left);    cout << root->data << " ";    inorder(root->right); } int main(void) {    struct Node* root = newNode(1);    root->left = newNode(2);    root->right = newNode(3);    root->left->left = newNode(3);    root->left->right = newNode(4);    root->right->right = newNode(5);    root->right->left = newNode(4);    root->right->right->left = newNode(4);    root->right->right->right = newNode(4);    deleteLeafNodes(root, 4);    cout << "Tree: ";    inorder(root);    cout << endl;    return 0; }

Output

If you execute the above code, then you will get the following result.

Tree: 3 2 1 3 5

Conclusion

If you have any queries in the tutorial, mention them in the comment section.