#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

unsigned int convert(char *hodnota)//funkce, ktera pretypuje N (vstup char a vystup unsigned int
{
unsigned int cislo=0,preteceni=0;
unsigned int i=0;
while(hodnota[i]!='\0')
  {
  if (hodnota[i]<='0' && hodnota[i]>'9') //osetreni, ze N je cislo (osetreni i pro to, ze cilo je kladne)
    {
    return 0;
    }
  hodnota[i]=hodnota[i]-'0';    //zaskani presne hodnoty cisla z nejake ascii hodnoty

  preteceni=cislo;
  cislo=cislo*10;
  cislo=cislo+hodnota[i]; //pokud uz proslo pripocte k 10tinasobku predchoziho cila prave nastene cislo
  i++;
  if(preteceni>cislo)   //doslo k preteceni - jednicka vypadla ven a jede se od nuly
    {
    return 0;       //kdyz vrati nulu - doslo k chybe (zde z duvodu preteceni)
    }
  }
return cislo;
}


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int komprimace(unsigned int N)
{
printf("Komprimace %d \n",N);
char *buffer1 = malloc((N+1) * sizeof(char));//definice bufferù a jejich dynamické alokování
char *buffer2 = malloc((N+1) * sizeof(char));

if(buffer1==NULL)
{
return 1;
}

if (buffer2==NULL)
{
return 1;
}
unsigned int i=0; //vlozeni pomocnych promenych (pocet je promena, do ktere se bude vkladat pocet shodujicich se blokù znakù)
char c=0;

while((c = getchar()) != EOF && i!=(2*N))
  {
    if(i < N)               //prvotní nacteni do bufferu ze vstupu
      {
      buffer1[i%N] = c;
      i++;
      }
      else if(i < 2 * N)
        {
        buffer2[i%N] = c;
        i++;
        }
  }
putchar(buffer1[0]);putchar(buffer1[1]);putchar(buffer1[2]);putchar(buffer2[0]);putchar(buffer2[1]);putchar(buffer2[2]);
printf("\nnad timto radkem je prvotni nactenido bufferu\n");
  while((c = getchar()) != EOF)             //vytisknuti prvniho znaku a posunuti znaku o jeden a nacteni dalsiho znaku
    {
    unsigned int j=0;
    putchar(buffer1[j%N]);
        printf("\n");
    while(j<(N-1))
      {
      buffer1[j%N]=buffer1[(j+1)%N];
      j++;
      }

        while(j==(N-1))
      {
      buffer1[j%N]=buffer2[(j+1)%N];     // PRESUNUTI PRVNIHO ZNAKU Z BUFFERU2 NA POSLEDNI ZNAK BUFFERU 1
            j++;
      }

    while ((j>(N-1)) && (j<((2*N)-1)))
      {
      buffer2[j%N]=buffer2[(j+1)%N];
      j++;
      }
        c=getchar();
        j++;
        c=buffer2[j%N];
        putchar (c);
        printf("\n");
    putchar(buffer1[0]);putchar(buffer1[1]);putchar(buffer1[2]);putchar(buffer2[0]);putchar(buffer2[1]);putchar(buffer2[2]);
        printf("\nnad timto radkem je posunuti o jeden\n");
    }

  unsigned int k=0, l=0;
  while(k < N)
      {
      putchar (buffer1[l%N]);
      k++;
      l++;
      printf ("K je : %d",k);
      while((k>=N) && k < (2 * (N-1)))
        {
        putchar (buffer2[l%N]);
        k++;
    l++;
        }
      }

free(buffer1);
free(buffer2);
return 0;
}


int main(int argc, char *argv[])
{
unsigned int N=(convert(argv[1]));
komprimace(N);
return 0;
}