Question

A prime number is an integer greater than 1 that is evenly divisible by only 1 and itself. For example, the number 5 is prime because it can only be evenly divided by 1 and 5. The number 6, however, is not prime because it can be divided by 1, 2, 3, and 6.

Write a Boolean function named isPrime, which takes an integer as an argument and returns true if the argument is a prime number, and false otherwise. Demonstrate the function in a complete program.

Your program must have at least 3 user-defined functions is as follows:

• get_input function

• isPrime function

• main function

Here's an algorithm to solve this problem:

// main function

do

{

// call get_input function to input a positive integer (whole numbers > 0)

// call isPrime function.

     // send the positive integer returned from get_input as an argument to isPrime.

// if the value returned from isPrime is true,

   // display that the input data (display the actual value of the number) is a prime number;

// else

   // display that the input data (display the actual value of the number) is not a prime number;

// prompt user to input an answer whether he/she wants to go through the above process with

// another positive integer.

// get the user’s answer.

} while (answer == ‘y’ || answer == ‘Y’)

// get_input function

// prompt the user to input an integer.

// do data validation on the entered integer;

// that is, set up a loop, and as long as the integer is not

// positive, have the user enter a positive integer.

//   once a positive integer is entered, that integer needs to be returned back to the main

// function.

// isPrime function

// this function receives a positive integer as a parameter.

// this function returns a value of true or false back to main.

in C++  

Answer 1

ANSWER:-

#include
using namespace std;
int get_input()
{
   int n;
   do
   {
       cout<<"enter a number : ";
       cin>>n;
   }while(n<=0);
return n;
}
bool isPrime(int n)
{
   if (n <= 1)
return false;
  
// Check from 2 to n-1
for (int i = 2; i < n; i++)
if (n % i == 0)
return false;

return true;
}
int main() {
   int n;
   char answer;
   bool res;
   do
   {
       n=get_input();
       res=isPrime(n);
       if(res)
       cout<<"the number "<        else
       cout<<"the number "<        cout<<"if you want above process again enter y/Y : ";
       cin>>answer;
   }while (answer == 'y' || answer == 'Y');
   return 0;
}

OUTPUT:-

enter a number : 5
the number 5 is prime 
if you want above process again enter y/Y : y
enter a number : 6
the number 6 is not prime 
if you want above process again enter y/Y : n