hash

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

typedef struct zaznam {
  char ID[9];
  struct zaznam *dalsi;
} ZAZNAM;

int hash(char *string)
{
  int i, len, result=1;
  len = strlen(string);
  for (i=0; i<len; i++)
  {
    if (i != 0)
    {
      result = result*2 + string[i];
    }
    else
    {
      result = string[i];
    }
  }
  return result;
}

// spracuje cisla OP: vrati pocet najdenych duplikatov.
int vyhadzovac(char *a[], int n)
{
  ZAZNAM **pole = (ZAZNAM**)malloc(5*n*sizeof(ZAZNAM*));
  int pocet=0, i, hashCode;
  ZAZNAM *pom;
  for (i=0; i<5*n; i++)
  {
    pole[i] = NULL;
  }
  for (i=0; i<n; i++)
  {
    hashCode = hash(a[i]);
    if (pole[hashCode % (5*n)] == NULL)
    {
      pole[hashCode % (5*n)] = malloc(sizeof(ZAZNAM));
      strcpy(pole[hashCode % (5*n)] -> ID, a[i]);
      pole[hashCode % (5*n)] -> dalsi = NULL;
    }
    else
    {
      pom = pole[hashCode % (5*n)];
      while (pom-> dalsi != NULL)
      {
        if (strcmp(pom -> ID, a[i]) == 0)
        {
          pocet+=1;
          break;
        }
        else
        {
          pom = pom -> dalsi;
        }
      }
      if (pom -> dalsi == NULL)
      {
        if (strcmp(pom -> ID, a[i]) == 0)
        {
          pocet+=1;
        }
        else
        {
          pom -> dalsi = malloc(sizeof(ZAZNAM));
          strcpy(pom -> dalsi -> ID, a[i]);
          pom -> dalsi -> dalsi = NULL;
        }
      }
    }
  }
  return pocet;
}

// ukazkovy test
int main(void)
{
  char **a = NULL, buf[100];
  int n = 0, len = 0;

  // nacitanie retazcov
  while(scanf("%s", buf) > 0)
  {
    if (n == len)
    {
      len = len + len + (len==0);
      a = (char**)realloc(a, len*sizeof(char*));
    }
    a[n++] = strdup(buf);
  }
  printf("Pocet duplikatov: %d\n", vyhadzovac(a, n));
  return 0;
}