it says cannot convert string to char please help, it needs to be string. c++ i will include the source main and .h classes //bt.cpp - file contains member functions #include "bt.h" #include using namespace std; //Constructor BT::BT() {     root = NULL; } //Insert new item in BST void BT::insert(string d) {     node* t = new node;     node* parent;     t->data = d;  //THE ERROR MESSAGE IS FROM HERE     t->left = NULL;     t->right = NULL;     parent = NULL;     if (isEmpty())         root = t;     else     {         //Note: ALL insertions are as leaf nodes         node* curr;         curr = root;         // Find the Node's parent         while (curr)         {             parent = curr;             if (t->data > curr->data)                 curr = curr->right;             else                 curr = curr->left;         }         if (t->data < parent->data)             parent->left = t;         else             parent->right = t;     } } ___________________________________________________________________________________________ #include "bt.h" #include #include using namespace std; int main() {     BT b;     int ch, num;     string d;     cout << "-----------Menu-------------" << endl;     cout << endl;     cout << "1. Insert node(s)" << endl;     cout << "2. Traverse Preorder" << endl;     cout << "3. Traverse Inorder" << endl;     cout << "4. Traverse Inorde" << endl;     cout << "5. Quit" << endl << endl;     do     {         cout << endl << "Enter Your Choice <1 - 5> ";         cin >> ch;         switch (ch)         {         case 1:             cout << "Enter number of nodes to insert: ";             cin >> num;             for (int i = 0; i> d;                 //b.insert(toupper(d));                 cout << "Inserted." << endl;             } ____________________________________________________________________________________________ //bt.h - header file contains the object description #include #ifndef BT_H #define BT_H using namespace std; class BT { private:     struct node     {         char data;  //whatever is the data type; use that         node* left;         node* right;     };     node* root; public:     BT();                                            //Constructor     bool isEmpty() const { return root == NULL; }    //Check for empty     void insert(string);                                //Insert item in BST }

it says cannot convert string to char please help, it needs to be string. c++ i will include the source main and .h classes

//bt.cpp - file contains member functions
#include "bt.h"
#include <iostream>
using namespace std;
//Constructor
BT::BT()
{
    root = NULL;
}

//Insert new item in BST
void BT::insert(string d)
{
    node* t = new node;
    node* parent;

    t->data = d;  //THE ERROR MESSAGE IS FROM HERE
    t->left = NULL;
    t->right = NULL;
    parent = NULL;

    if (isEmpty())
        root = t;
    else
    {
        //Note: ALL insertions are as leaf nodes
        node* curr;
        curr = root;
        // Find the Node's parent
        while (curr)
        {
            parent = curr;
            if (t->data > curr->data)
                curr = curr->right;
            else
                curr = curr->left;
        }
        if (t->data < parent->data)
            parent->left = t;
        else
            parent->right = t;
    }
}

___________________________________________________________________________________________

#include "bt.h"
#include<string>
#include <iostream>
using namespace std;
int main()
{
    BT b;
    int ch, num;
    string d;

    cout << "-----------Menu-------------" << endl;
    cout << endl;
    cout << "1. Insert node(s)" << endl;
    cout << "2. Traverse Preorder" << endl;
    cout << "3. Traverse Inorder" << endl;
    cout << "4. Traverse Inorde" << endl;
    cout << "5. Quit" << endl << endl;

    do
    {
        cout << endl << "Enter Your Choice <1 - 5> ";
        cin >> ch;
        switch (ch)
        {
        case 1:
            cout << "Enter number of nodes to insert: ";
            cin >> num;
            for (int i = 0; i<num; i++)
            {
                cout << endl;
                cout << "Enter node: ";
                cin >> d;
                //b.insert(toupper(d));
                cout << "Inserted." << endl;

            }

____________________________________________________________________________________________

//bt.h - header file contains the object description
#include <iostream>
#ifndef BT_H
#define BT_H
using namespace std;

class BT
{
private:
    struct node
    {
        char data;  //whatever is the data type; use that
        node* left;
        node* right;
    };
    node* root;
public:
    BT();                                            //Constructor
    bool isEmpty() const { return root == NULL; }    //Check for empty
    void insert(string);                                //Insert item in BST

}