I need help for the following assignment in C++.

Using the supplied Binary Search Tree code, add a 'copy' method to the BST class which will create a copy of a populated binary search tree. Modify the 'display' method so that it can display either the original tree or the new one. Before doing the copy, populate the original tree with at least 10 nodes.

# include # include

using namespace std; /* * Node Declaration */ struct node { int info; struct node *left; struct node *right; }*root;

/* * Class Declaration */ class BST { public: void find(int, node **, node **); //void insert(int); // bdd - commented out void insert(node *, node *); // bdd - added void del(int); void case_a(node *, node *); void case_b(node *, node *); void case_c(node *, node *); void preorder(node *); void inorder(node *); void postorder(node *); void display(node *, int); BST() { root = NULL; } }; /* * Main Contains Menu */ int main() { int choice, num; BST bst; node *temp; while (1) { cout << "-----------------" << endl; cout << "Operations on BST" << endl; cout << "-----------------" << endl; cout << "1.Insert Element " << endl; cout << "2.Delete Element " << endl; cout << "3.Inorder Traversal" << endl; cout << "4.Preorder Traversal" << endl; cout << "5.Postorder Traversal" << endl; cout << "6.Display" << endl; cout << "7.Quit" << endl; cout << "Enter your choice : "; cin >> choice; switch (choice) { case 1: temp = new node; cout << "Enter the number to be inserted : "; cin >> temp->info; bst.insert(root, temp); break; // bdd - added case 2: if (root == NULL) { cout << "Tree is empty, nothing to delete" << endl; continue; } cout << "Enter the number to be deleted : "; cin >> num; bst.del(num); break; case 3: cout << "Inorder Traversal of BST:" << endl; bst.inorder(root); cout << endl; break; case 4: cout << "Preorder Traversal of BST:" << endl; bst.preorder(root); cout << endl; break; case 5: cout << "Postorder Traversal of BST:" << endl; bst.postorder(root); cout << endl; break; case 6: cout << "Display BST:" << endl; bst.display(root, 1); cout << endl; break; case 7: exit(1); default: cout << "Wrong choice" << endl; } } }

/* * Find Element in the Tree */ void BST::find(int item, node **par, node **loc) { node *ptr, *ptrsave; if (root == NULL) { *loc = NULL; *par = NULL; return; } if (item == root->info) { *loc = root; *par = NULL; return; } if (item < root->info) ptr = root->left; else ptr = root->right; ptrsave = root; while (ptr != NULL) { if (item == ptr->info) { *loc = ptr; *par = ptrsave; return; } ptrsave = ptr; if (item < ptr->info) ptr = ptr->left; else ptr = ptr->right; } *loc = NULL; *par = ptrsave; }

/* * Inserting Element into the Tree */ void BST::insert(node *tree, node *newnode) { if (root == NULL) { root = new node; root->info = newnode->info; root->left = NULL; root->right = NULL; cout << "Root Node is Added" << endl; return; } if (tree->info == newnode->info) { cout << "Element already in the tree" << endl; return; } if (tree->info > newnode->info) { if (tree->left != NULL) { insert(tree->left, newnode); } else { tree->left = newnode; (tree->left)->left = NULL; (tree->left)->right = NULL; cout << "Node Added To Left" << endl; return; } } else { if (tree->right != NULL) { insert(tree->right, newnode); } else { tree->right = newnode; (tree->right)->left = NULL; (tree->right)->right = NULL; cout << "Node Added To Right" << endl; return; } } }

/* * Delete Element from the tree */ void BST::del(int item) { node *parent, *location; if (root == NULL) { cout << "Tree empty" << endl; return; } find(item, &parent, &location); if (location == NULL) { cout << "Item not present in tree" << endl; return; } if (location->left == NULL && location->right == NULL) case_a(parent, location); if (location->left != NULL && location->right == NULL) case_b(parent, location); if (location->left == NULL && location->right != NULL) case_b(parent, location); if (location->left != NULL && location->right != NULL) case_c(parent, location); free(location); }

/* * Case A */ void BST::case_a(node *par, node *loc) { if (par == NULL) { root = NULL; } else { if (loc == par->left) par->left = NULL; else par->right = NULL; } }

/* * Case B */ void BST::case_b(node *par, node *loc) { node *child; if (loc->left != NULL) child = loc->left; else child = loc->right; if (par == NULL) { root = child; } else { if (loc == par->left) par->left = child; else par->right = child; } }

/* * Case C */ void BST::case_c(node *par, node *loc) { node *ptr, *ptrsave, *suc, *parsuc; ptrsave = loc; ptr = loc->right; while (ptr->left != NULL) { ptrsave = ptr; ptr = ptr->left; } suc = ptr; parsuc = ptrsave; if (suc->left == NULL && suc->right == NULL) case_a(parsuc, suc); else case_b(parsuc, suc); if (par == NULL) { root = suc; } else { if (loc == par->left) par->left = suc; else par->right = suc; } suc->left = loc->left; suc->right = loc->right; }

/* * Pre Order Traversal */ void BST::preorder(node *ptr) { if (root == NULL) { cout << "Tree is empty" << endl; return; } if (ptr != NULL) { cout << ptr->info << " "; preorder(ptr->left); preorder(ptr->right); } } /* * In Order Traversal */ void BST::inorder(node *ptr) { if (root == NULL) { cout << "Tree is empty" << endl; return; } if (ptr != NULL) { inorder(ptr->left); cout << ptr->info << " "; inorder(ptr->right); } }

/* * Postorder Traversal */ void BST::postorder(node *ptr) { if (root == NULL) { cout << "Tree is empty" << endl; return; } if (ptr != NULL) { postorder(ptr->left); postorder(ptr->right); cout << ptr->info << " "; } }

/* * Display Tree Structure */ void BST::display(node *ptr, int level) { int i; if (ptr != NULL) { display(ptr->right, level + 1); cout << endl; if (ptr == root) cout << "Root->: "; else { for (i = 0; i < level; i++) cout << " "; } cout << ptr->info; display(ptr->left, level + 1); } }