Program to create Mirror image of a binary tree.

Question :

Write a Program in Java to print the mirror image of a given binary tree. Example is provided in following diagram

Solution :

Do a normal BFS traversal. In each call copy the left child's content to create right node of the mirror tree and the right child's content to create left child.

Code : 

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public class TreeMirrorImageCreator {       public static Node createMirrorImage(Node originalNode,Node mirroredNode){           mirroredNode.setValue(originalNode.getValue());           if(originalNode.getRight() != null){             mirroredNode.setLeft(createMirrorImage(originalNode.getRight(),new Node(0)));         }           if(originalNode.getLeft() != null){             mirroredNode.setRight(createMirrorImage(originalNode.getLeft(), new Node(0)));         }           return mirroredNode;       } }

Now lets write the code to test out this code.

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public static void main(String args[]){           Node root = new Node(1);           Node l = new Node(2);         Node r = new Node(3);           Node l1 = new Node(12);         Node l2 = new Node(13);           Node r1 = new Node(6);         Node r2 = new Node(8);           root.setLeft(l);         root.setRight(r);           l.setLeft(l1);         l.setRight(l2);           r.setLeft(r1);         r.setRight(r2);           System.out.println("Orig Tree : ");         LevelTraversal.printLeveltraversal(root);         Node mirroredRoot = new Node(0);         TreeMirrorImageCreator.createMirrorImage(root,mirroredRoot);         System.out.println("Mirrored Tree : ");         LevelTraversal.printLeveltraversal(mirroredRoot); }

Note :  Code for the Node data structure and level order traversal can be found here.

Related Links

• DataStructures github link