user: Please show me the C implementation that matches the assembly code listed below:

```asm
<getop>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x30,%rsp
  mov    %rdi,-0x28(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x8(%rbp)
  xor    %eax,%eax
  nop
L251:
  mov    $0x0,%eax
  call   <getch@plt>
  mov    %eax,-0x18(%rbp)
  mov    -0x18(%rbp),%eax
  mov    %eax,%edx
  mov    -0x28(%rbp),%rax
  mov    %dl,(%rax)
  mov    -0x28(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x20,%al
  je     L251
  cmpl   $0x9,-0x18(%rbp)
  je     L251
  mov    -0x28(%rbp),%rax
  add    $0x1,%rax
  movb   $0x0,(%rax)
  cmpl   $0x25,-0x18(%rbp)
  je     L110
  cmpl   $0x2b,-0x18(%rbp)
  je     L110
  cmpl   $0x2f,-0x18(%rbp)
  je     L110
  cmpl   $0xa,-0x18(%rbp)
  je     L110
  cmpl   $0x2a,-0x18(%rbp)
  jne    L99
L110:
  mov    -0x18(%rbp),%eax
  jmp    L75
L99:
  movl   $0x0,-0x1c(%rbp)
  cmpl   $0x2d,-0x18(%rbp)
  jne    L137
  mov    $0x0,%eax
  call   <getch@plt>
  mov    %eax,-0x18(%rbp)
  cmpl   $0x20,-0x18(%rbp)
  je     L35
  cmpl   $0x9,-0x18(%rbp)
  je     L35
  mov    D29(%rip),%rax
  mov    (%rax),%eax
  cmp    %eax,-0x18(%rbp)
  je     L35
  cmpl   $0xa,-0x18(%rbp)
  jne    L158
L35:
  mov    -0x18(%rbp),%eax
  mov    %eax,%edi
  call   <ungetch@plt>
  mov    $0x2d,%eax
  jmp    L75
L158:
  mov    -0x18(%rbp),%eax
  mov    %eax,%edi
  call   <ungetch@plt>
L137:
  mov    -0x18(%rbp),%eax
  movsbl %al,%eax
  mov    %eax,%edi
  call   <isdigit@plt>
  test   %rax,%rax
  jne    L42
  cmpl   $0x2e,-0x18(%rbp)
  je     L42
  cmpl   $0x2d,-0x18(%rbp)
  je     L42
  nop
L79:
  mov    $0x0,%eax
  call   <getch@plt>
  mov    %eax,-0x18(%rbp)
  addl   $0x1,-0x1c(%rbp)
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    -0x18(%rbp),%edx
  mov    %dl,(%rax)
  movzbl (%rax),%eax
  cmp    $0x20,%al
  je     L245
  mov    D29(%rip),%rax
  mov    (%rax),%eax
  cmp    %eax,-0x18(%rbp)
  je     L245
  cmpl   $0xa,-0x18(%rbp)
  je     L245
  cmpl   $0x9,-0x18(%rbp)
  jne    L79
L245:
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  movb   $0x0,(%rax)
  mov    D29(%rip),%rax
  mov    (%rax),%eax
  cmp    %eax,-0x18(%rbp)
  je     L171
  mov    -0x18(%rbp),%eax
  mov    %eax,%edi
  call   <ungetch@plt>
L171:
  mov    $0x31,%eax
  jmp    L75
L42:
  mov    -0x18(%rbp),%eax
  movsbl %al,%eax
  mov    %eax,%edi
  call   <isdigit@plt>
  test   %rax,%rax
  je     L279
  nop
L259:
  mov    $0x0,%eax
  call   <getch@plt>
  mov    %eax,-0x18(%rbp)
  addl   $0x1,-0x1c(%rbp)
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    -0x18(%rbp),%edx
  mov    %dl,(%rax)
  movzbl (%rax),%eax
  movsbl %al,%eax
  mov    %eax,%edi
  call   <isdigit@plt>
  test   %rax,%rax
  jne    L259
L279:
  cmpl   $0x2e,-0x18(%rbp)
  jne    L241
  nop
L89:
  mov    $0x0,%eax
  call   <getch@plt>
  mov    %eax,-0x18(%rbp)
  addl   $0x1,-0x1c(%rbp)
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  mov    -0x18(%rbp),%edx
  mov    %dl,(%rax)
  movzbl (%rax),%eax
  movsbl %al,%eax
  mov    %eax,%edi
  call   <isdigit@plt>
  test   %rax,%rax
  jne    L89
L241:
  mov    -0x1c(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x28(%rbp),%rax
  add    %rdx,%rax
  movb   $0x0,(%rax)
  mov    D29(%rip),%rax
  mov    (%rax),%eax
  cmp    %eax,-0x18(%rbp)
  je     L114
  mov    -0x18(%rbp),%eax
  mov    %eax,%edi
  call   <ungetch@plt>
L114:
  mov    $0x30,%eax
L75:
  mov    -0x8(%rbp),%rdx
  sub    %fs:0x28,%rdx
  je     L103
  call   <__stack_chk_fail@plt>
L103:
  leave
  ret
```

assistant: ```c
int getop(char s[]) {
  int i, c;
  char word[10];
  while ((s[0] = c = getch()) == ' ' || c == '\t')
    ;
  s[1] = '\0';
  if (c == '%' || c == '+' || c == '/' || c == '\n' || c == '*') {
    return c;
  }
  i = 0;
  if (c == '-') {
    if ((c = getch()) == ' ' || c == '\t' || c == EOF || c == '\n') {
      ungetch(c);
      return '-';
    } else
      ungetch(c);
  }
  if (!isdigit(c) && c != '.' && c != '-') {
    while ((s[++i] = c = getch()) != ' ' && c != EOF && c != '\n' && c != '\t')
      ;
    s[i] = '\0';
    if (c != EOF)
      ungetch(c);
    return '1';
  }
  if (isdigit(c))
    while (isdigit(s[++i] = c = getch()))
      ;
  if (c == '.') {
    while (isdigit(s[++i] = c = getch()))
      ;
  }
  s[i] = '\0';
  if (c != EOF)
    ungetch(c);
  return '0';
}
```