Prime Number Program in C

Program 1

// Program for Prime Number
// Program for prime number
#include<stdio.h>
#include<conio.h>
  
int main()
{
     system("cls");
      int n,i=2,f=0;
      printf("Enter a number");
      scanf("%d",&n);
      while(i<n)
      {
           if(n%i==0)
           {
              f=1;
              break;
           }
           i++;
      }
      if(f==0)
        printf("No is prime");
     else
          printf("No is not prime"); 


}