Question

NASA has decided to go back and use modems to communicate between computers (they must have missed the War Games video). In order to provide security, the last 6 digits of the phone number must add to 33. If the fourth number is odd the fifth number must be even. Likewise, if the fourth number is even the fifth number must be odd.

Write a phone number generator that asks for the first four digits. The computer must generate a list of all possible phone numbers that meet the new security rule, and display them as follows:

(XXX) - XXX - XXXX

Answer 1

#include <iostream>

#include <cstdlib>

#include <ctime>

using namespace std;

int main()

{

   int i = 0;

   char playAgain;

   do

   {

       //random number generator

       srand (static_cast<unsigned int>(time(0)));

       //define variables

       int firstFour[5];

      int lastSix[7];

       //Greeting and input of first four numbers

       cout<<"\n\n\t\tWelcome to the NASA's modem number generator"<<endl

<<"\t\tYou will enter the first four digits of the phone number, "<<endl

<<"\t\tand then be given options for the last six numbers. "<<endl

<<"\n\t\tEnter the first four desired numbers: ";

       //while statement to input numbers to array

       for(int i = 0; i < 4; i++)

       {

           cout<<"\n\t\t";

           cout<<i + 1<<". ";

           cin>>firstFour[i];

       }

       //do loop to check if == to 33

       int j=0;

       do

       {

           int i = 0;

           //check if 4th number is even

           if(firstFour[3] % 2 == 0)

           {

               do

               {

                   lastSix[0] = rand() % 9;

               }while(lastSix[0] % 2 == 0);

               for(int i = 1; i < 6; i++)

               {

                   lastSix[i] = rand() % 10;

               }

           }else

               if(firstFour[3] % 2 != 0)

               {

                   do

                   {

                       lastSix[0] = rand() % 10;

                   }while(lastSix[0] % 2 != 0);

               }

               for(int i = 1; i < 6; i++)

               {

                   lastSix[i] = rand()% 10;

               }

               int sum = 0;

               for (int i=0; i<6; i++)

               {

                   sum+= lastSix[i];

               }

             

               if(sum == 33)

               {

                   //display chosen number

                   cout<<"(";

                   for(int i = 0; i < 3; i++)

                   {

               cout<<firstFour[i];

                   }

cout<<")-"<<firstFour[3]<<lastSix[0]<<lastSix[1]<<"-";

                   for(int i = 2; i< 6; i++)

                   {

                       cout<<lastSix[i];

                   }

                   cout<<"\n";

               }

               j++;

       }while(j < 500);

       cout<<"Run again?";

       cin>> playAgain;

   }while (playAgain == 'y');

   system("pause");

   return 0;

}

Sample Output:

                        Welcome to the NASA's modem number generator

                        Enter the first four digits of the phone number,

                        and then give options for the last six numbers.

                        Enter the first four desired numbers:

                        1. 3

                        2. 4

                        3. 5

                        4. 6

(345)-672-4839

(345)-639-6465

(345)-675-6537

(345)-679-5534

(345)-655-7169

(345)-651-7398

(345)-656-7735

(345)-659-7291

(345)-636-8970

(345)-618-7944

(345)-639-6672

Run again? N