user: 提供的汇编代码用C语言表示会是什么样子：

```asm
<expand>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  mov    %rdi,-0x18(%rbp)
  mov    %rsi,-0x20(%rbp)
  movl   $0x0,-0x8(%rbp)
  movl   $0x0,-0x4(%rbp)
  jmp    L61
L118:
  mov    -0x8(%rbp),%eax
  cltq
  lea    0x1(%rax),%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  cmp    $0x2d,%al
  jne    L161
  movzbl -0xb(%rbp),%eax
  mov    %al,-0xa(%rbp)
  mov    -0x8(%rbp),%eax
  cltq
  lea    0x2(%rax),%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  mov    %al,-0x9(%rbp)
  cmpb   $0x60,-0xa(%rbp)
  jle    L137
  cmpb   $0x7a,-0x9(%rbp)
  jg     L137
  movzbl -0xa(%rbp),%eax
  cmp    -0x9(%rbp),%al
  jge    L137
  movzbl -0xa(%rbp),%eax
  mov    %al,-0xb(%rbp)
  jmp    L148
L83:
  mov    -0x4(%rbp),%eax
  lea    0x1(%rax),%edx
  mov    %edx,-0x4(%rbp)
  movslq %eax,%rdx
  mov    -0x20(%rbp),%rax
  add    %rax,%rdx
  movzbl -0xb(%rbp),%eax
  mov    %al,(%rdx)
  movzbl -0xb(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0xb(%rbp)
L148:
  movzbl -0xb(%rbp),%eax
  cmp    -0x9(%rbp),%al
  jle    L83
  addl   $0x2,-0x8(%rbp)
  jmp    L87
L137:
  cmpb   $0x40,-0xa(%rbp)
  jle    L25
  cmpb   $0x5a,-0x9(%rbp)
  jg     L25
  movzbl -0xa(%rbp),%eax
  cmp    -0x9(%rbp),%al
  jge    L25
  movzbl -0xa(%rbp),%eax
  mov    %al,-0xb(%rbp)
  jmp    L4
L140:
  mov    -0x4(%rbp),%eax
  lea    0x1(%rax),%edx
  mov    %edx,-0x4(%rbp)
  movslq %eax,%rdx
  mov    -0x20(%rbp),%rax
  add    %rax,%rdx
  movzbl -0xb(%rbp),%eax
  mov    %al,(%rdx)
  movzbl -0xb(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0xb(%rbp)
L4:
  movzbl -0xb(%rbp),%eax
  cmp    -0x9(%rbp),%al
  jle    L140
  addl   $0x2,-0x8(%rbp)
  jmp    L87
L25:
  cmpb   $0x2f,-0xa(%rbp)
  jle    L74
  cmpb   $0x39,-0x9(%rbp)
  jg     L74
  movzbl -0xa(%rbp),%eax
  cmp    -0x9(%rbp),%al
  jge    L74
  movzbl -0xa(%rbp),%eax
  mov    %al,-0xb(%rbp)
  jmp    L115
L162:
  mov    -0x4(%rbp),%eax
  lea    0x1(%rax),%edx
  mov    %edx,-0x4(%rbp)
  movslq %eax,%rdx
  mov    -0x20(%rbp),%rax
  add    %rax,%rdx
  movzbl -0xb(%rbp),%eax
  mov    %al,(%rdx)
  movzbl -0xb(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0xb(%rbp)
L115:
  movzbl -0xb(%rbp),%eax
  cmp    -0x9(%rbp),%al
  jle    L162
  addl   $0x2,-0x8(%rbp)
  jmp    L87
L74:
  mov    -0x4(%rbp),%eax
  lea    0x1(%rax),%edx
  mov    %edx,-0x4(%rbp)
  movslq %eax,%rdx
  mov    -0x20(%rbp),%rax
  add    %rax,%rdx
  movzbl -0xb(%rbp),%eax
  mov    %al,(%rdx)
  jmp    L87
L161:
  mov    -0x4(%rbp),%eax
  lea    0x1(%rax),%edx
  mov    %edx,-0x4(%rbp)
  movslq %eax,%rdx
  mov    -0x20(%rbp),%rax
  add    %rax,%rdx
  movzbl -0xb(%rbp),%eax
  mov    %al,(%rdx)
L87:
  addl   $0x1,-0x8(%rbp)
L61:
  mov    -0x8(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  movzbl (%rax),%eax
  mov    %al,-0xb(%rbp)
  cmpb   $0x0,-0xb(%rbp)
  jne    L118
  mov    -0x4(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x20(%rbp),%rax
  add    %rdx,%rax
  movb   $0x0,(%rax)
  nop
  pop    %rbp
  ret
```

assistant: ```c
void expand(char s1[], char s2[]) {
  int i = 0;
  int j = 0;
  char c;
  char start, end;
  while ((c = s1[i]) != '\0') {
    if (s1[i + 1] == '-') {
      start = c;
      end = s1[i + 2];
      if (start >= 'a' && end <= 'z' && start < end) {
        for (c = start; c <= end; ++c)
          s2[j++] = c;
        i = i + 2;
      } else if (start >= 'A' && end <= 'Z' && start < end) {
        for (c = start; c <= end; ++c)
          s2[j++] = c;
        i = i + 2;
      } else if (start >= '0' && end <= '9' && start < end) {
        for (c = start; c <= end; ++c)
          s2[j++] = c;
        i = i + 2;
      } else
        s2[j++] = c;
    } else
      s2[j++] = c;
    ++i;
  }
  s2[j] = '\0';
  return;
}
```