macOS pls give me some idea to my password code

[letarik]

#include<iostream>
#include <math.h>
#include <windows.h>                  // For   Sleep function
#include <ctime>                      // For Displaying time
#include <iomanip>
#include <limits>
#include <conio.h>
#include <stdlib.h>
#include <fstream>
#include <ctype.h>                  // For isalpha() function
using namespace std;
void taxcalc();
void calcultor();

void time();
void loading();
void menu();
void mainEntrance();
//void call();
void mainmenu();
void login();


            

void time()
{
    //  FOR current time and date
    //
        time_t now;  
    time (&now);
    cout << "\n\n\t\t Current Date & Time is: "<<ctime(&now);;         // For Displaying Date and Time  
    // Creating Object of Time

}  


void loading()
{
    //(24,26);
    int i;
    for (i=0; i<5; i++)
    {
        cout << "\xdb\xdb\xdb\xdb\xdb";
        Sleep(100);
    }
    Sleep(500);
    cout << endl << endl;
    //(24,28);
}
  
    void mainEntrance()
  
{
    //(15,2);
cout<<"\tÛÛÛÛÛ  \t\t\tÛÛÛÛÛÛÛÛ    \tÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛÛ             "<<endl;
cout<<"\t ÛÛÛ  \t\t\tÛÛÛ             ÛÛ\tÛÛÛ      ÛÛ    "<<endl;
cout<<"\t ÛÛÛ  \t\t\tÛÛÛ             \tÛÛÛ                "<<endl;
cout<<"\t ÛÛÛ  \t\t\tÛÛÛÛÛÛÛÛ        \tÛÛÛ                 "<<endl;
cout<<"\t ÛÛÛ  \t\t\tÛÛÛ             \tÛÛÛ                 "<<endl;
cout<<"\t ÛÛÛ  \t\t\tÛÛÛ             \tÛÛÛ               "<<endl;
cout<<"\tÛÛÛÛÛÛÛÛÛÛÛÛ  \t\tÛÛÛÛÛÛÛÛ     \tÛÛÛ               "<<endl<<endl;
cout << "     **************************************************************" << endl;

cout << "                       ma first applications                     " << endl;

cout << "     **************************************************************" << endl;
}

void login()
{
    system("cls");

    string username = "";
    string password = "";
    char ch,ch2,retry;
    int i = 0, j = 0;
    mainEntrance();
    time();  
  
    cout << "(LOGIN)";
  
    cout << "\n\n\t\tEnter Username: \t\t    Enter Password: ";

    cout<<endl;
    ch2=getch();
    while(ch2 != 13){                  // gets input until 'Enter' key is pressed
  
        if(ch2 == '\b'){
            if(username.size() > 0 )  {
                username.erase(username.begin() + username.size() -1);
                cout << "\b \b";
                j--;
            }
            ch2 = getch();
        }
        else{
            if(j<10)
            {
                cout << ch2;
                username.push_back(ch2);
                ch2 = getch();
                j++;
            }
            else{
                ch2 = getch();
            }
        }
    }
  

    ch=getch();
    cout<<endl;
    while(ch != 13){                  // gets input until 'Enter' key is pressed
  

        if(ch == '\b'){
            if(password.size() > 0){
                password.erase(password.begin() + password.size() -1);
                cout << "\b \b";
                i--;
            }
            ch = getch();
        }
        else{
            if(i<10)
            {
                password.push_back(ch);
                cout << "*";                      // For showing stars instead of actual alphabets
                ch = getch();
                i++;
            }
            else{
                ch = getch();
            }
        }
    }
    if (username == "letarik" && password == "1012")
    {
        //(15,16);
        cout << "\n\n Username & Password Matched !! ";
        cout << "\n\n\t Access Granted...\n\n";
        cout << "\n\n\t\t Now Loading: ";
        loading();
        return;
    }  
    else
    {
        system("cls");
        cout << "\n\n You entered Wrong UserName/Password ";
        cout << "\n\n\t Press 'R' or 'r' to Enter Again OR any other key to exit ...\n\n";
        cin >> retry;  
            if(retry == 'r' || retry == 'R')
            {
                system("cls");
                login();
            }
            else
            {
                exit(0);
            }
    }
}

          

void menu()
{
    cout<<"\n\t\tchose what u want to do\n\n";
    cout<<"\t\tenter ur choice(integer 1-11) \n\n";
    cout<<"\t\t---------  Welcome  ---------\n";
    cout<<"\t\t1--------->  simple calculator\n";
    cout<<"\t\t2--------->  simple tax calc\n";
    //cout<<"\t\t3--------->  super mrkt billing app calc\n";
    cout<<"\t\t4--------->  main manu\n";
    cout<<"\t\t5--------->  exit app\n";

  
int x;
        cin>>x;
      
        switch(x)
    {
  

        case 4:
            mainmenu();
            system("pause");
            break;  
          
        case 5:
            exit(0);
            break;      
        default:
            cout << "\n\n Please Enter a valid Choice: \n\n";
            system ("pause");
            break;
        }
      
}

 void mainmenu()
 {
    menu();
 }


 int main()
{
    system("color 0D");
    login();
  
    while(true)
  
    {
      
            system("cls");
            mainmenu();
            menu();
          
          
    }
    return 1;
}