Hacktober

MirrorOfBinaryTree.cpp

@@ -0,0 +1,98 @@
+// C++ program to convert a binary tree
+// to its mirror
+#include <bits/stdc++.h>
+using namespace std;
+
+/* A binary tree node has data, pointer
+to left child and a pointer to right child */
+struct Node {
+	int data;
+	struct Node* left;
+	struct Node* right;
+};
+
+/* Helper function that allocates a new node with
+the given data and NULL left and right pointers. */
+struct Node* newNode(int data)
+{
+	struct Node* node
+		= (struct Node*)malloc(sizeof(struct Node));
+	node->data = data;
+	node->left = NULL;
+	node->right = NULL;
+
+	return (node);
+}
+
+/* Change a tree so that the roles of the left and
+	right pointers are swapped at every node.
+
+So the tree...
+	4
+	/ \
+2 5
+/ \
+3 1
+
+is changed to...
+	4
+	/ \
+5 2
+	/ \
+	1 3
+*/
+void mirror(struct Node* node)
+{
+	if (node == NULL)
+		return;
+	else {
+		struct Node* temp;
+
+		/* do the subtrees */
+		mirror(node->left);
+		mirror(node->right);
+
+		/* swap the pointers in this node */
+		temp = node->left;
+		node->left = node->right;
+		node->right = temp;
+	}
+}
+
+/* Helper function to print
+Inorder traversal.*/
+void inOrder(struct Node* node)
+{
+	if (node == NULL)
+		return;
+
+	inOrder(node->left);
+	cout << node->data << " ";
+	inOrder(node->right);
+}
+
+// Driver Code
+int main()
+{
+	struct Node* root = newNode(1);
+	root->left = newNode(2);
+	root->right = newNode(3);
+	root->left->left = newNode(4);
+	root->left->right = newNode(5);
+
+	/* Print inorder traversal of the input tree */
+	cout << "Inorder traversal of the constructed"
+		<< " tree is" << endl;
+	inOrder(root);
+
+	/* Convert tree to its mirror */
+	mirror(root);
+
+	/* Print inorder traversal of the mirror tree */
+	cout << "\nInorder traversal of the mirror tree"
+		<< " is \n";
+	inOrder(root);
+
+	return 0;
+}
+