Question

1. Write a RECURSIVE function, swapSubtrees, that swaps all of the left and right subtrees of a binary tree.

void swapSubtrees(TreeNode *p)

need In C++ language please

Answer 1

FUNCTION TO SWAP LEFT AND RIGHT SUBTREES OF A BINARY TREE:

void swapSubtrees(TreeNode *p){

    if(p == NULL)

        return;

    swapSubtrees(p->left);

    swapSubtrees(p->right);

    // Swap subtrees

    TreeNode* temp = p->left;

    p->left = p->right;

    p->right = temp;

}

C++ CODE TO DEMONSTRATE ABOVE FUNCTION:

#include<iostream>

using namespace std;

/*This structure represents a TreeNode or sub-tree in the BST*/

struct TreeNode{

    int data;

    TreeNode *left, *right;

};

/*Function prototypes*/

void preorderTraversal(TreeNode *);

void inorderTraversal(TreeNode *);

void postorderTraversal(TreeNode *);

void swapSubtrees(TreeNode *);

/*Main function of the program*/

int main(){

    // Create a binary tree

    TreeNode *tree = NULL;

    tree = new TreeNode;

    tree->data = 1;

    tree->left = new TreeNode;

    tree->left->data = 2;

    tree->right = new TreeNode;

    tree->right->left = tree->right->right = NULL;

    tree->right->data = 3;

    tree->left->left = new TreeNode;

    tree->left->left->data = 4;

    tree->left->left->left = tree->left->left->right = NULL;

    tree->left->right = new TreeNode;

    tree->left->right->left = tree->left->right->right = NULL;

    tree->left->right->data = 5;

    cout << "Before Swapping subtrees:\n";

    cout << "Preorder:\t";

    preorderTraversal(tree);

    cout << "\nInorder:\t";

    inorderTraversal(tree);

    cout << "\nPostorder:\t";

    postorderTraversal(tree);

    

    // Swap subtrees

    swapSubtrees(tree);

    

    cout << "\n\nAfter Swapping subtrees:\n";

    cout << "Preorder:\t";

    preorderTraversal(tree);

    cout << "\nInorder:\t";

    inorderTraversal(tree);

    cout << "\nPostorder:\t";

    postorderTraversal(tree);

    return 0;

}

// Function to swap left and right subtree of binary tree

void swapSubtrees(TreeNode *p){

    if(p == NULL)

        return;

    swapSubtrees(p->left);

    swapSubtrees(p->right);

    // Swap subtrees

    TreeNode* temp = p->left;

    p->left = p->right;

    p->right = temp;

}

void preorderTraversal(TreeNode *tree){

    if(tree != NULL){

        printf("%d\t", tree->data);

        preorderTraversal(tree->left);

        preorderTraversal(tree->right);

    }

}

void inorderTraversal(TreeNode *tree){

    if(tree != NULL){

        inorderTraversal(tree->left);

        printf("%d\t", tree->data);

        inorderTraversal(tree->right);

    }

}

void postorderTraversal(TreeNode *tree){

    if(tree != NULL){

        postorderTraversal(tree->left);

        postorderTraversal(tree->right);

        printf("%d\t", tree->data);

    }

}

OUTPUT:

BINARY TREE USED IN ABOVE OUTPUT BEFORE SWAPPING SUBTREES:

BINARY TREE USED IN ABOVE OUTPUT AFTER SWAPPING SUBTREES:

FOR ANY HELP JUST DROP A COMMENT