#define __NO_STRING_INLINES

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

char s1[] = "abcdefghijklmnopqrstuvwxyz";

void
test (char *s1, int i, int test, int len)
{
  char s2[2 * len + 1];
  int j, k;

  for (k = i; k <= len + 1; k++)
    for (j = 0; j < len; j++)
      {
        memcpy (s2 + j, s1, len + 1);
        s2[i+j] += test;
        assert (memcmp (s2 + j, s1, k) == (k != i ? test : 0));
      }
}

main()
{
  int len = strlen(s1);
  int i, h;

  for (h = 0; h < len; h += 5)
    for (i = h; i < len; i++)
      {
        test (s1 + h, i - h, -1, len);
        test (s1 + h, i - h, 0, len);
        test (s1 + h, i - h, 1, len);
      }

  exit (0);
}