DSAL_AS Ass 2

#include <iostream>
using namespace std;

class Node {
public:
    int data;
    Node *left;
    Node *right;
};

class BST {
private:
    Node *root;
public:
    BST() {
        root = nullptr;
    }

    void createTree() {

        Node *temp, *curr;

        do {
            temp = new Node;
            cout << "Enter data: "; cin >> temp->data;
            temp->left = temp->right = nullptr;

            if (root == nullptr) {
                root = temp;
            } else {
                curr = root;
                while (1) {
                    // Left
                    if (temp->data < curr->data) {
                        if (curr->left == nullptr) {
                            curr->left = temp;
                            break;
                        } else {
                            curr = curr->left;
                        }
                    }
                    // Right
                    if (temp->data >= curr->data) {
                        if (curr->right == nullptr) {
                            curr->right = temp;
                            break;
                        } else {
                            curr = curr->right;
                        }
                    }
                }

            }

            int flag;
            cout << "Want to enter a new node? (0 for NO): "; cin >> flag;
            if (flag == 0) break;

        } while (true);

    }

    void preorder(Node *root) {
        if (root == nullptr) return;

        cout << root->data << "\t";
        preorder(root->left);
        preorder(root->right);
    }

    void postorder(Node *root) {
        if (root == nullptr) return;

        preorder(root->left);
        preorder(root->right);
        cout << root->data << "\t";
    }

    void inorder(Node *root) {
        if (root == nullptr) return;
        preorder(root->left);
        cout << root->data << "\t";
        preorder(root->right);
    }

    void displayTree() {
        if (root == nullptr) {
            cout << "Tree empty" << endl;
        } else {
            cout << "Display" << endl;
            int choice;
            cout << "1. Postorder" << endl;
            cout << "2. Inorder" << endl;
            cout << "3. Preorder" << endl;
            cout << "4. All" << endl;
            cout << "Enter choice: " << endl; cin >> choice;

            if (choice == 1) {
                cout << "Postorder Traversal: " << endl;
                postorder(root);
            cout << endl;
            } else if (choice == 2) {
                cout << "Inorder Traversal: " << endl;
                inorder(root);
                cout << endl;
            } else if (choice == 3) {
                cout << "Preorder Traversal: " << endl;
                preorder(root);
                cout << endl;
            } else if (choice == 4) {
                cout << "Postorder Traversal: " << endl;
                postorder(root);
                cout << endl;
                cout << "Inorder Traversal: " << endl;
                inorder(root);
                cout << endl;
                cout << "Preorder Traversal: " << endl;
                preorder(root);
                cout << endl;
            } else {
                cout << "Invalid Input" << endl;
            }
        }
    }
};


int main() {
    BST Tree;
    Tree.createTree();
    Tree.displayTree();

    cout << "\nEnding program" << endl;
    return 0;
}