[C++] 厦大C语言上机 1265 字符串后继

#include <stdio.h>
#include <string.h>
void reverse(char *s, int len)
{
  int i, j;
  char temp;
  for (i = 0, j = len-1; i < j; ++i, --j)
  {
    temp = s[i];
    s[i] = s[j];
    s[j] = temp;
  }
}
void print_successor(char *s, int n)
{
  int len_s;
  int carry, dump;
  int i, j;
  len_s = (int)strlen(s);
  for (j = 1; j <= n; ++j)
  {
    reverse(s, len_s);
    if ('0' <= s[0] && s[0] <= '9')
    {
      carry = (s[0] - '0' + 1) / 10;
      s[0] = (char)((s[0] - '0' + 1) % 10 + '0');
    }
    else if ('a' <= s[0] && s[0] <= 'z')
    {
      carry = (s[0] - 'a' + 1) / 26;
      s[0] = (char)((s[0] - 'a' + 1) % 26 + 'a');
    }
    else
    {
      carry = (s[0] - 'A' + 1) / 26;
      s[0] = (char)((s[0] - 'A' + 1) % 26 + 'A');
    }
    for (i = 1; i < len_s; ++i)
    {
      if ('0' <= s[i] && s[i] <= '9')
      {
        dump = (s[i] - '0' + carry) / 10;
        s[i] = (char)((s[i] - '0' + carry) % 10 + '0');
        carry = dump;
      }
      else if ('a' <= s[i] && s[i] <= 'z')
      {
        dump = (s[i] - 'a' + carry) / 26;
        s[i] = (char)((s[i] - 'a' + carry) % 26 + 'a');
        carry = dump;
      }
      else
      {
        dump = (s[i] - 'A' + carry) / 26;
        s[i] = (char)((s[i] - 'A' + carry) % 26 + 'A');
        carry = dump;
      }
    }
    while (carry > 0)
    {
      if ('0' <= s[i-1] && s[i-1] <= '9')
      {
        dump = carry / 10;
        s[i] = (char)(carry % 10 + '0');
        carry = dump;
      }
      else if ('a' <= s[i-1] && s[i-1] <= 'z')
      {
        dump = carry / 26;
        s[i] = (char)(carry % 26 + 'a' - 1);
        carry = dump;
      }
      else
      {
        dump = carry / 26;
        s[i] = (char)(carry % 26 + 'A' - 1);
        carry = dump;
      }
      ++i;
    }
    s[i] = '\0';
    len_s = i;
    reverse(s, len_s);
    printf("%s\n", s);
  }
}
int main()
{
  char s[205] = { 0 };
  int n;
  scanf("%s %d", s, &n);
  print_successor(s, n);
  return 0;
}