user: 请将这段汇编代码片段转换成等效的C代码:

```asm
<main>:
  endbr64
  push   %rbp
  push   %rbx
  sub    $0xb8,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0xa8(%rsp)
  xor    %eax,%eax
  movl   $0x62616362,0x11(%rsp)
  movw   $0x63,0x15(%rsp)
  movl   $0x636261,0x8(%rsp)
  lea    0x11(%rsp),%rdi
  call   <removeDuplicateLetters@plt>
  mov    %rax,%rbx
  lea    0x8(%rsp),%rdi
  mov    %rax,%rsi
  call   <strcmp@plt>
  test   %rax,%rax
  sete   %dil
  movzbl %dil,%edi
  call   <assert@plt>
  lea    D19(%rip),%rdi
  call   <printf@plt>
  mov    %rbx,%rdi
  call   <free@plt>
  movabs $0x6362636463616263,%rax
  mov    %rax,0x17(%rsp)
  movb   $0x0,0x1f(%rsp)
  movl   $0x62646361,0xc(%rsp)
  movb   $0x0,0x10(%rsp)
  lea    0x17(%rsp),%rdi
  call   <removeDuplicateLetters@plt>
  mov    %rax,%rbx
  lea    0xc(%rsp),%rdi
  mov    %rax,%rsi
  call   <strcmp@plt>
  test   %rax,%rax
  sete   %dil
  movzbl %dil,%edi
  call   <assert@plt>
  lea    D0(%rip),%rbp
  mov    %rbp,%rdi
  call   <printf@plt>
  mov    %rbx,%rdi
  call   <free@plt>
  movabs $0x7469747173656874,%rax
  movabs $0x6f6c787074657978,%rdx
  mov    %rax,0x60(%rsp)
  mov    %rdx,0x68(%rsp)
  movabs $0x6669716564766565,%rax
  mov    %rax,0x70(%rsp)
  movw   $0x7a6b,0x78(%rsp)
  movb   $0x0,0x7a(%rsp)
  movabs $0x7079787469736568,%rax
  movabs $0x7a6b667164766f6c,%rdx
  mov    %rax,0x20(%rsp)
  mov    %rdx,0x28(%rsp)
  movb   $0x0,0x30(%rsp)
  lea    0x60(%rsp),%rdi
  call   <removeDuplicateLetters@plt>
  mov    %rax,%rbx
  lea    0x20(%rsp),%rdi
  mov    %rax,%rsi
  call   <strcmp@plt>
  test   %rax,%rax
  sete   %dil
  movzbl %dil,%edi
  call   <assert@plt>
  mov    %rbp,%rdi
  call   <printf@plt>
  mov    %rbx,%rdi
  call   <free@plt>
  movabs $0x6875726c6e74696d,%rax
  movabs $0x746d7a79666a6e7a,%rdx
  mov    %rax,0x80(%rsp)
  mov    %rdx,0x88(%rsp)
  movabs $0x77787374736e666d,%rax
  movabs $0x75786f626c78746b,%rdx
  mov    %rax,0x90(%rsp)
  mov    %rdx,0x98(%rsp)
  movl   $0x63696274,0xa0(%rsp)
  movb   $0x0,0xa4(%rsp)
  movabs $0x7a79666a68726c69,%rax
  movabs $0x6f626b7774736e6d,%rdx
  mov    %rax,0x40(%rsp)
  mov    %rdx,0x48(%rsp)
  movl   $0x637578,0x50(%rsp)
  lea    0x80(%rsp),%rdi
  call   <removeDuplicateLetters@plt>
  mov    %rax,%rbx
  lea    0x40(%rsp),%rdi
  mov    %rax,%rsi
  call   <strcmp@plt>
  test   %rax,%rax
  sete   %dil
  movzbl %dil,%edi
  call   <assert@plt>
  mov    %rbp,%rdi
  call   <printf@plt>
  mov    %rbx,%rdi
  call   <free@plt>
  mov    0xa8(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L4
  mov    $0x0,%eax
  add    $0xb8,%rsp
  pop    %rbx
  pop    %rbp
  ret
L4:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: read_data
arguments: label: D19
data_type: string
name: read_data
arguments: label: D0
data_type: string

tool: D19: First case: OK


tool: D0: Second case: OK


assistant: ```c
int main() {
  char s1[] = "bcabc";
  char expected1[] = "abc";
  char *result1 = removeDuplicateLetters(s1);
  assert(strcmp(expected1, result1) == 0);
  printf("First case: OK\n");
  free(result1);
  char s2[] = "cbacdcbc";
  char expected2[] = "acdb";
  char *result2 = removeDuplicateLetters(s2);
  assert(strcmp(expected2, result2) == 0);
  printf("Second case: OK\n");
  free(result2);
  char s3[] = "thesqtitxyetpxloeevdeqifkz";
  char expected3[] = "hesitxyplovdqfkz";
  char *result3 = removeDuplicateLetters(s3);
  assert(strcmp(expected3, result3) == 0);
  printf("Second case: OK\n");
  free(result3);
  char s4[] = "mitnlruhznjfyzmtmfnstsxwktxlboxutbic";
  char expected4[] = "ilrhjfyzmnstwkboxuc";
  char *result4 = removeDuplicateLetters(s4);
  assert(strcmp(expected4, result4) == 0);
  printf("Second case: OK\n");
  free(result4);
  return 0;
}
```