PA1 - úkol 2.1 (palindromy)

#include <stdio.h>
#include <limits.h>

unsigned long long int reverse ( unsigned long long int num );

int main ( int argc, char * argv[] )
 {
    unsigned long long int n;
    int i = 0;

    puts ( "Zadejte cislo:" );
    if ( scanf ( "%llu", &n ) != 1 || n < 0 )
     {
        puts ( "Nespravny vstup." );
        return 1;
     }

    while ( n != reverse ( n ) )
     {
        if ( ULLONG_MAX / 10 > n )
         {
            n += reverse ( n );
         }
        else
         {
            puts ( "Palindrom nenalezen." );
            return 0;
         }
        i++;
     }
    printf ( "Vypocteny palindrom: %llu (iteraci: %d)\n", n, i );

    return 0;
 }

unsigned long long int reverse ( unsigned long long int num )
 {
    unsigned long long int r,reverse=0;

    while ( num )
     {
         r=num%10;
         reverse *=10;
         reverse +=r;
         num=num/10;
     }
    return reverse;
 }