Delete leaf nodes with value as x
Given a binary tree and a target integer x, delete all the leaf nodes having value as x. Also, delete the newly formed leaves with the target value as x.
Example:
Input : x = 5
6
/ \
5 4
/ \ \
1 2 5
Output :
6
/ \
5 4
/ \
1 2
Inorder Traversal is 1 5 2 6 4
Source: Microsoft Interview
We traverse the tree in postorder fashion and recursively delete the nodes. The approach is very similar to this and this problem.
C++
// CPP code to delete all leaves with given// value.#include <bits/stdc++.h>using namespace std; // A binary tree nodestruct Node { int data; struct Node *left, *right;}; // A utility function to allocate a new nodestruct Node* newNode(int data){ struct Node* newNode = new Node; newNode->data = data; newNode->left = newNode->right = NULL; return (newNode);} Node* deleteLeaves(Node* root, int x){ if (root == NULL) return nullptr; root->left = deleteLeaves(root->left, x); root->right = deleteLeaves(root->right, x); if (root->data == x && root->left == NULL && root->right == NULL) { return nullptr; } return root;} void inorder(Node* root){ if (root == NULL) return; inorder(root->left); cout << root->data << " "; inorder(root->right);} // Driver programint main(void){ struct Node* root = newNode(10); root->left = newNode(3); root->right = newNode(10); root->left->left = newNode(3); root->left->right = newNode(1); root->right->right = newNode(3); root->right->right->left = newNode(3); root->right->right->right = newNode(3); deleteLeaves(root, 3); cout << "Inorder traversal after deletion : "; inorder(root); return 0;} |
Java
// Java code to delete all leaves with given // value. class GfG { // A binary tree node static class Node { int data; Node left, right; } // A utility function to allocate a new node static Node newNode(int data) { Node newNode = new Node(); newNode.data = data; newNode.left = null; newNode.right = null; return (newNode); } static Node deleteLeaves(Node root, int x) { if (root == null) return null; root.left = deleteLeaves(root.left, x); root.right = deleteLeaves(root.right, x); if (root.data == x && root.left == null && root.right == null) { return null; } return root; } static void inorder(Node root) { if (root == null) return; inorder(root.left); System.out.print(root.data + " "); inorder(root.right); } // Driver program public static void main(String[] args) { Node root = newNode(10); root.left = newNode(3); root.right = newNode(10); root.left.left = newNode(3); root.left.right = newNode(1); root.right.right = newNode(3); root.right.right.left = newNode(3); root.right.right.right = newNode(3); deleteLeaves(root, 3); System.out.print("Inorder traversal after deletion : "); inorder(root); }} |
Python3
# Python3 code to delete all leaves # with given value. # A utility class to allocate a new node class newNode: def __init__(self, data): self.data = data self.left = self.right = None def deleteLeaves(root, x): if (root == None): return None root.left = deleteLeaves(root.left, x) root.right = deleteLeaves(root.right, x) if (root.data == x and root.left == None and root.right == None): return None return root def inorder(root): if (root == None): return inorder(root.left) print(root.data, end = " ") inorder(root.right) # Driver Codeif __name__ == '__main__': root = newNode(10) root.left = newNode(3) root.right = newNode(10) root.left.left = newNode(3) root.left.right = newNode(1) root.right.right = newNode(3) root.right.right.left = newNode(3) root.right.right.right = newNode(3) deleteLeaves(root, 3) print("Inorder traversal after deletion : ") inorder(root) # This code is contributed by PranchalK |
C#
// C# code to delete all leaves with given // value.using System; class GfG { // A binary tree node class Node { public int data; public Node left, right; } // A utility function to allocate a new node static Node newNode(int data) { Node newNode = new Node(); newNode.data = data; newNode.left = null; newNode.right = null; return (newNode); } static Node deleteLeaves(Node root, int x) { if (root == null) return null; root.left = deleteLeaves(root.left, x); root.right = deleteLeaves(root.right, x); if (root.data == x && root.left == null && root.right == null) { return null; } return root; } static void inorder(Node root) { if (root == null) return; inorder(root.left); Console.Write(root.data + " "); inorder(root.right); } // Driver code public static void Main(String[] args) { Node root = newNode(10); root.left = newNode(3); root.right = newNode(10); root.left.left = newNode(3); root.left.right = newNode(1); root.right.right = newNode(3); root.right.right.left = newNode(3); root.right.right.right = newNode(3); deleteLeaves(root, 3); Console.Write("Inorder traversal after deletion : "); inorder(root); }} // This code is contributed by PrinciRaj1992 |
Output:
Inorder traversal after deletion : 3 1 10 10
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