I receive compilation error but in Borland C++ all ok.
What is problem?

#include<iostream.h>
#include<stdlib.h>
#include<string.h>

void main()
{
    unsigned long N, K, i, position;
    char * mas[30000];
    char * mas1[30000];
    char * mas2[30000];
    char * mas3[10000];

    cin>>N;
    cin>>K;


    for( i = 1 ; i <= N; i++)
    {
      if(i < 30000)
      {
        ultoa(i, mas[i - 1], 10/* size(i)*/);
      }
      else if (i < 60000)
      {
        ultoa(i,  mas1[i - 30001] , 10/* size(i)*/);
      }
      else if (i < 90000)
      {
        ultoa(i,  mas2[i - 60001] , 10/*size(i)*/);
      }
      else if (i < 100000)
      {
        ultoa(i,  mas3[i - 90001] , 10/*size(i)*/);
      }
    }

    i = 0;
    position = 0;
    int step = 0;
    while( i < N)
    {
        while(step < K)
        {
            if(position >= N)
                position = position - N;
            if(position < 30000)
            {
                if(strcmp(mas[position], "0") != 0)
                    step ++;
            }
            else if(position < 60000)
            {
                if(strcmp(mas[position - 30000], "0") != 0)
                    step ++;
            }
            else if(position < 90000)
            {
                if(strcmp(mas[position - 60000], "0") != 0)
                    step ++;
            }
            else if(position < 100000)
            {
                if(strcmp(mas[position - 90000], "0") != 0)
                    step ++;
            }
            position++;
        }
        step = 0;
        position --;
        if(position < 30000)
        {
            cout<<mas[position];
            mas[position] = "0";
        }
        else if(position < 60000)
        {
            cout<<mas1[position];
            mas1[position] = "0";
        }
        else if(position < 90000)
        {
            cout<<mas2[position];
            mas2[position] = "0";
        }
        else if(position < 100000)
        {
            cout<<mas3[position];
            mas3[position] = "0";
        }
        cout<<" ";
        i++;
        position ++;
    }
}