/* This program is for checking a single integer*/
#include<stdio.h>
#include<stdlib.h>
main()
{
 int a,i;
 printf("\nEnter a positive integer\n");
 scanf("%d",&a);
 if(a<=0)
 {
  printf("\nInvalid input\n");
  exit(1);
 }
 for(i=2;i<=a-1;i++)
   if(a%i==0)break;
 if(i==a)printf("\n%d is prime\n",a);
 else printf("\n%d is not a prime\n",a);
}
 
 
/* This is for elements in an array*/
#include<stdio.h>
#include<stdlib.h>
#define MAX 5
main()
{
 int a[MAX],i,m;
 printf("\nEnter elements into array\n");
 for(m=0;m<=MAX-1;m++)
 {
    scanf("%d",&a[m]);
    if(a[m]>0)
    {
          for(i=2;i<=a[m]-1;i++) if(a[m]%i==0)break;
          if(i==a[m])printf("\n%d is prime\n",a[m]);
          else printf("\n%d is not a prime\n",a[m]);
    }
    else printf("\n%d is not positive\n");
 }
}