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  1. #include <stdio.h>
  2.  
  3. long int emirp(long int x){
  4.    long int i,flag=0,reverse=0,rem;
  5.    if(x==1||x==2||x==3||x==5||x==7){
  6.             return 0;
  7.       }
  8.    while(x!=0) {
  9.        rem=x%10;
  10.        reverse=reverse*10+rem;
  11.        x/=10;
  12.        }
  13.    for(i=2;i<=reverse/2;++i) {
  14.            if(reverse%i==0) {
  15.                 flag=1;
  16.                 break;
  17.                 }
  18.                 }
  19.                 if(flag==0){
  20.                 return 2;
  21.                 }
  22.           else{
  23.           return 0;
  24.           }
  25.     }
  26.  
  27. int main()
  28. {
  29.     long int i,n=0,flag=0,k;
  30.     while(scanf("%ld",&n)==1){
  31.         flag=0;
  32.       for(i=2;i<=n/2;++i) {
  33.            if(n%i==0) {
  34.                 flag=1;
  35.                 break;
  36.                 }
  37.                 }
  38.       if(flag==0){
  39.       k=emirp(n);
  40.       if(k==2)
  41.       printf("%ld is emirp.\n",n);
  42.  
  43.       else
  44.       printf("%ld is prime.\n",n);
  45.  
  46.  
  47.       }
  48.  
  49.       else{
  50.       printf("%ld is not prime.\n",n);
  51.       }
  52.  
  53.  
  54.     }
  55.     return 0;
  56. }
  57.  
Success #stdin #stdout 0s 2292KB
comments (?)
stdin 
Standard input is empty
stdout 
Standard output is empty
https://ideone.com/NeMde2
language:
C (gcc 8.3)
created:
11 years ago
visibility:
public

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