Question

Objectives: Integer arithmetic, Functions, menus.

Write a C++ program that displays the following menu of choices.

1. Find the number of digits in an integer.
2. Find the nth digit in an integer.
3. Find the sum of all digits of an integer.
4. Is the integer a palindrome?

5. Quit
Enter a choice:

Page 1 of 4

For each of the choices (1, 3, 4), Read a positive integer number and call a function that processes the menu choice (descriptions below). For option 2 read two positiveintegers. If the n value is invalid, print an error message and display the menu again. Your program should continuously display the menu until the user enters 5 to quit. Any other choice should be ignored and display the menu again.

Required Functions (use the provided prototype and function names):

• Option 1, int getNumDigits(int number):Return the number of digits in number.

• Option 2, int getNthDigit(int number, int n):Return the digit number specified by n. Right most digit is digit one.

• Option 3, int getSumDigits(int number):Return the total value of all the digits.

• Option 4, bool isPalindrome(int number):
  returns true if the number is a palindrome (1, 121, 1221, 134431, etc.). False otherwise.

• A function (int getInteger()) that returns a positive integer. This function should loop until the user enters a positive integer.

  All of the above functions must only manipulate integers. Do not use string types or arrays in any part of this project.

Answer 1

#include<iostream>
using namespace std;
//method to count the number of digits of a number
int getNumDigits(int number)
{
   int c=0,r;
   //loop will continue till the number !=0
   while(number!=0)
   {
      r=number%10;
      c++; //count the number of digits
      number=number/10; //reduce the number
   }
   return c; //return the count
}
//method to return the nth position digit of a number
int getNthDigit(int number,int n)
{
int c=0,r;
//loop will continue till the number !=0
    while(number!=0)
   {
      r=number%10;
      c++; //count the number of digits of a number
      if(c==n) //if value of c and n equal then return the digit i.e/ r
      return r;
      number=number/10; //reduce the number
   }
   return 0;
}
//returns the sum of digits of a number
int getSumDigit(int number)
{
   int sum=0,r;
   //loop will continue till the number !=0
    while(number!=0)
   {
      r=number%10; //fidn the individual digits of a number
      sum=sum+r; //find the sum
       number=number/10;//reduce the number
   }
   return sum; //return the sum
  
}
//method to check a number a spalindrome or not
bool isPalindrome(int number)
{
    int n,rev=0,r;
    n=number;
    //loop will continue till the number !=0
    while(number!=0)
   {
      r=number%10; //find the individual digit of a number
      rev = rev*10 + r; //fidn the reverse of a number
       number=number/10;//reduce the number
   }
   if(rev==n) //compare the reverse and number if equal then return true otherwise return false
   return true;
   else
   return false;
}
//method to return a +ve integer
int getInteger()
{
   int n;
   //loop will terminate when user enter a +vce integer
   do
   {
      cout<<endl<<"Enter a +ve integer";
      cin>>n; //read the value
       }while(n<=0); //if -ve then loop will continue
       return n; //return the n
   }
   //method to control the menu()
   void menu()
   {
      int opt,n,No;
      //infinite loop
      while(1)
      {
         //display the menu
             cout<<endl<<" 1. Find the number of digits in an integer";
      cout<<endl<<" 2. Find the Nth digit in an integer";
      cout<<endl<<" 3. Find the sum of all digits of an integer";
      cout<<endl<<" 4. Is the integer a palindrome ? ";
      cout<<endl<<" 5. Quit";
      cout<<endl<<"Enter your choice";
      cin>>opt; //read the choice
      if(opt==1) //block for find the number of digits of a number
      {
         n=getInteger(); //read the +ve integer
         //display the number of digits
         cout<<endl<<"The number of digits in "<<n<<" is :"<<getNumDigits(n);
       }
       else
       if(opt==2)
       {
          n=getInteger(); //read the +ve integer
         
          cout<<endl<<"Enter the value of which position digit you want to print";
          cin>>No; //read the position
          if(No>getNumDigits(n)) //check the validity of the position
          cout<<endl<<"Your Position exceeds to the number of digits in the number";
          else
          { //if position is valid then return the digit of that position
             cout<<endl<<"The "<<No<<" th Digit of "<<n<<" is "<<getNthDigit(n,No);
               }
              
       }
       else
       if(opt==3)
       {
           n=getInteger(); //read the +ve integer
           //display the sum of digits of the number
           cout<<endl<<"Sum of digits of "<<n<<" is "<<getSumDigit(n);
           }
           else
           if (opt==4)
           {
              n=getInteger(); //read the +ve integer
              if(isPalindrome(n)) //check palindrome
              cout<<endl<<n<<" is palindrome";
              else
              cout<<endl<<n<<" is not a palindrome";
           }
           else
           if(opt==5)
           exit(0); //quit the program
           else
           cout<<endl<<"Invalid Choice"; //invalid choice
      
       }
     
     
   }
   int main()
   {
      //call to menu() to control the program
      menu();
   }

OUTPUT