C program to make prime numbers or check prime numbers

C program to make prime numbers or check prime numbers

Problem 1:

Write a  C program to check if the number is prime or not.

Solution:

logic for being a prime number:

C Code for check if the number is prime or not:

#include <stdio.h>
int main()
{
   int n, c = 2;
 
   printf("Enter a number to check if it is prime = \n");
   scanf("%d",&n);
 
   for ( c = 2 ; c <= n - 1 ; c++ )
   {
      if ( n%c == 0 )
      {
        printf("%d is not prime.\n", n);
     break;
      }
   }
   if ( c == n )
      printf("%d is prime.\n", n);
 
   return 0;
}

Run Code for check if the number is prime or not in Live [Give input 12 or 19 to check]:

Problem 2:

Write a  C program to generate number of prime numbers.

C code for generate number of prime numbers:

#include <stdio.h>
int main()
{
   int n, i = 3, count, c;
 
   printf("Enter the number of prime numbers required\n");
   scanf("%d",&n);
 
   if ( n >= 1 )
   {
      printf("First %d prime numbers are :\n",n);
      printf("2\n");
   }
 
   for ( count = 2 ; count <= n ;  )
   {
      for ( c = 2 ; c <= i - 1 ; c++ )
      {
         if ( i%c == 0 )
            break;
      }
      if ( c == i )
      {
         printf("%d\n",i);
         count++;
      }
      i++;
   }
 
   return 0;
}

Tags:
C program to make prime numbers or check prime numbers, C program to generate prime, prime number generating, C code,  c programming examples, c codes, prime number algorithm