• Skip to primary navigation
  • Skip to content
  • Skip to primary sidebar
  • Skip to secondary sidebar

GoHired

Interview Questions asked in Google, Microsoft, Amazon

Join WeekEnd Online Batch from 4-April-2020 on How to Crack Coding Interview in Just 10 Weeks : Fees just 20,000 INR

  • Home
  • Best Java Books
  • Algorithm
  • Internship
  • Certificates
  • About Us
  • Contact Us
  • Privacy Policy
  • Array
  • Stack
  • Queue
  • LinkedList
  • DP
  • Strings
  • Tree
  • Mathametical
  • Puzzles
  • Graph

Binary Tree Isomorphic to each other

March 22, 2017 by Dhaval Dave

Find weather two given trees are isomorphic to each other or not.
Lets understand What is isomorphic strings

AAB and XXY are IsoMorphic to each other, consider A replaces/morphs as X and B as Y, then both strings are isomorphic.
ABC and XXY are not IsoMorphic.isomorohic tree

In case of Trees Two binary trees A and B are isomorphic if they have the same shape means the values stored in the nodes do not affect whether two trees are isomorphic. Or its even called Quasi Isomorphic tree
(Mathematically we are discussing IsoMorphic rooted tree and not IsoMorphic Binary Tree, See at  : https://www.slideshare.net/AnasAssayuti/nota-math-discrete-tree Slide 28 onwards

Write a method isIsomorphic that returns true if its two tree are isomorphic and false otherwise.

Here w’ll discuss both ways to find if a tree is isomorphic to each other or not, One is with data and one is without data match

  1.  If ‘A’ Tree is structure wise mirror of other tree ‘B’ ( without its data values)
  2.  If ‘A’ Tree is exactly mirror of other tree ‘B’ (with of its data values

Algorithm for 1.

  • If any of the tree is null
    • Trees are not quasi isomorphic & return false
  • Check both trees tree1 and tree2
    • if tree1 and tree2 are null, traversal completed successfully.
      return true
  • Traverse Left subtree of tree1 and left subtree of tree2
  • Traverse Right subtree of tree1 and right subtree of tree2
    • If structures are identical, then return true
    • If trees are not identical, let us check one tree (or subtree) are mirror of other tree (subtree)
  • Traverse Left subtree of tree1 and right subtree of tree2
  • Traverse Right subtree of tree1 and left subtree of tree2
    • If structures are mirror structure, then return true
    • Else, return false

Sudo Code for 1&2.

bool isomorphic(struct treenode *treeone, struct treenode *treetwo)
{
    //if both tree null
    if (!treeone && !treetwo)
        return true;  
    // if one is null
    if((!treeone  ||  !treetwo))
        return false;
    // in case you want to check Data (case 2)
    if(treeone-data != treetwo->data)
        return false;
    return (
         (isomorphic(treeone->left, treetwo->left) 
          && isomorphic(treeone->right, treetwo->right)) || 
         (isomorphic(treeone->left, treetwo->right) 
          && isomorphic(treeone->right, treetwo->left))
         );
}

Working Code

// A C++ program to check if two given trees are isomorphic by gohired.in
#include <iostream>
using namespace std;

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

bool isIsomorphic(node *treeone, node *treetwo)
{
    if (!treeone && !treetwo)
        return true;  
    if((!treeone  ||  !treetwo))
        return false;
   
        return (
                isIsomorphic(treeone->left, treetwo->right) 
                && isIsomorphic(treeone->right, treetwo->left)
                ||
                isIsomorphic(treeone->left, treetwo->left) 
                && isIsomorphic(treeone->right, treetwo->right) 
            );
}

node* newNode(int data)
{
	node* temp = new node;
	temp->data = data;
	temp->left = NULL;
	temp->right = NULL;

	return (temp);
}
int main()
{
	struct node *n1 = newNode(1);
    n1->left        = newNode(2);
    n1->right       = newNode(3);
    n1->left->left  = newNode(4);
    n1->left->right = newNode(5);
    n1->right->left  = newNode(6);
    n1->left->right->left = newNode(7);
    n1->left->right->right = newNode(8);
 
    struct node *n2 = newNode(1);
    n2->left         = newNode(3);
    n2->right        = newNode(2);
    n2->right->left   = newNode(4);
    n2->right->right   = newNode(5);
    n2->left->right   = newNode(6);
    n2->right->right->left = newNode(8);
    n2->right->right->right = newNode(9);

	if (isIsomorphic(n1, n2) == true)
	cout << "Yes";
	else
	cout << "No";

	return 0;
}

Similar Articles

Filed Under: Amazon Interview Question, Interview Questions, Microsoft Interview Questions, problem Tagged With: Binary Tree, tree

Reader Interactions

Primary Sidebar

Join WeekEnd Online/Offline Batch from 4-April-2020 on How to Crack Coding Interview in Just 10 Weeks : Fees just 20,000 INR

Join WeekEnd Online/Offline Batch from 4-April-2020

WhatsApp us

Secondary Sidebar

Custom Search

  • How I cracked AMAZON
  • LeetCode
  • Adobe
  • Amazon
  • Facebook
  • Microsoft
  • Hacker Earth
  • CSE Interview

Top Rated Questions

Generic Object Oriented Stack with Template

VMWare Openings

Find shortest distances between every pair of vertices ( Dynamic Programming Floyd Warshall Algorithm)

25 horses 5 tracks Find 3 fastest puzzle

N teams are participating. each team plays twice with all other teams. Some of them will go to the semi final. Find Minimum and Maximum number of matches that a team has to win to qualify for finals ?

Find if a binary tree is height balanced ?

Python Dictionaries

LeetCode: Container With Most Water

Find the number ABCD such that when multipled by 4 gives DCBA.

Generate largest number arranging a no. of given non negative integer numbers

SAP Off Campus Hiring_ March 2015 Verbal Skills

Test Cases for Round Function

Regular Expression Matching

How Radix sort works

Memory Efficient LinkedList

How strtok() Works

Trapping Rain Water

Amazon Interview Experience – SDE Chennai

Sort Stack in place

Skiing on Mountains Matrix

Daughter’s Age VeryGood Puzzle

Print vertical sum of all the axis in the given binary tree

Fibonacci Hashing & Fastest Hashtable

Serialise Deserialise N-ary Tree

Implement a generic binary search algorithm for Integer Double String etc

Reverse a Linked List in groups of given size

Level order traversal in Spiral form

Given Set of words or A String find whether chain is possible from these words or not

Rectangular chocolate bar Create at least one piece which consists of exactly nTiles tiles

strtok()

Copyright © 2025 · Genesis Framework · WordPress · Log in