Question

write a program to input a number and find the frequency of prime digits in it using c++ and also do the dryrun​

Answer 1

Answer:

Examples:

Input: N = 12

Output: 1

Explanation:

Digits of the number – {1, 2}

But, only 2 is prime number.

Input: N = 1032

Output: 2

Explanation:

Digits of the number – {1, 0, 3, 2}

3 and 2 are prime number

Approach: The idea is to iterate through all the digits of the number and check whether the digit is a prime or not. Since there are only four possible prime numbers in the range [0, 9] and every digit for sure lies in this range, we only need to check the number of digits equal to either of the elements in the set {2, 3, 5, 7}.

Answer 2

Answer:

The details attached

Explanation:

#include <stdio.h>

#include <conio.h>

int main()

{

   int n, i, flag = 0;

   clrscr();

   printf("Enter a positive integer: ");

   scanf("%d",&n);

   for(i=2; i<=n/2; ++i)

   {

       // condition for nonprime number

       if(n%i==0)

       {

           flag=1;

           break;

       }

   }

   if (flag==0)

       printf("%d is a prime number.",n);

   else

printf("%d is not a prime number.",n);

   getch();

   

   return 0;

}