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manusik
Jan '21

Ssup fellow coders
I just started my journey with spoj and I keep encoutering runtime error.
I tried to do the palindrome task. Here is my code (c#)
using System;
using System.Collections.Generic;

namespace Testowanie
{
    class Program
    {
        public static string Reverse(string s)
        {
            char[] charArray = s.ToCharArray();
            Array.Reverse(charArray);
            return new string(charArray);
        }
        public static bool checkStrings(string a, string b)
        {
            if (a.Length != b.Length)
                return false;
            for(int i = 0; i<a.Length/2; i++)
            {
                if (a[i] != b[i])
                    return false;
            }
            return true;
        }
        static void Main(string[] args)
        {
            int t = Convert.ToInt32(Console.ReadLine());
            List<double> lista = new List<double>();
            for (int i = 0; i < t; i++)
            {
                double nowy = Convert.ToDouble(Console.ReadLine());
                lista.Add(nowy);
            }
            foreach(var i in lista)
            {
                double zwiekszona = i + 1;
                string liczba = zwiekszona.ToString();
                string liczbaOdwrotna = Reverse(liczba);
                while (!checkStrings(liczba, liczbaOdwrotna))
                {
                    zwiekszona++;
                    liczba = zwiekszona.ToString();
                    liczbaOdwrotna = Reverse(liczba);
                }
                Console.WriteLine(liczba);                
            }
      
        }
    }
}

Whenever I try to submit this badboy I get a runtime error (NZEC). Sb please tell me why is this occuring?
Here is a link to the task : https://www.spoj.com/problems/PALIN/3

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    Jan '21

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    Jan '21
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simes
Jan '21

Welcome to SPOJ.

Despite the large number of solvers, this problem isn’t as easy as it might first appear.

Did you notice the maximum size of the integer? I think test cases like this could be the cause of your problem.

1
999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999991

manusik
Jan '21

Thanks for your response, Simes!
The test case that you proposed indeed makes my program crash. However, should I use a try catch error statement if in the tasks description there is “For a given positive integer K of not more than 1000000 digits” ? Doesn’t that mean the SPOJ won’t test my program on numbers bigger than 10^6?

simes
Jan '21
1

For a given positive integer K of not more than 1000000 digits

Read that bit again… 1000000 digits, 10^6 is only seven digits. The test case is valid.