user: 请从给定的汇编指令推导出C源代码:

```asm
<sc>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  mov    %rdi,%rbp
  push   %rbx
  sub    $0x8,%rsp
  call   <strlen@plt>
  mov    $0x4,%edi
  mov    %eax,%r12d
  call   <malloc@plt>
  mov    %r12d,%edx
  mov    %rbp,%rsi
  mov    %rax,%rdi
  mov    %rax,%r13
  call   <strncpy@plt>
  test   %r12d,%r12d
  jle    L241
  mov    $0x2,%r15d
  xor    %r14d,%r14d
  mov    $0x1,%r8d
L49:
  lea    0x1(%r14),%eax
  mov    %r15d,%esi
  mov    %r14d,%edi
  cmp    %eax,%r12d
  jl     L206
  movzbl 0x0(%rbp,%r14,1),%edx
  lea    0x1(%r14),%rax
  mov    $0x1,%ebx
  jmp    L116
  nopl   0x0(%rax)
L3:
  add    $0x1,%rax
  add    $0x1,%ebx
  cmp    %eax,%r12d
  jl     L206
L116:
  mov    %eax,%ecx
  cmp    0x0(%rbp,%rax,1),%dl
  je     L3
  cmp    $0x1,%ebx
  je     L215
  sub    %ebx,%r12d
  movslq %r15d,%rax
  lea    0x1(%r12),%edx
  cmp    %r15d,%edx
  jl     L104
  mov    %r12d,%edx
  mov    %r8,%r10
  sub    %edi,%edx
  movslq %ebx,%rdi
  sub    %rdi,%r10
  lea    -0x1(%rdx),%r9d
  lea    (%rdi,%r14,1),%rcx
  cmp    $0xe,%r10
  jbe    L135
  cmp    $0x6,%r9d
  jbe    L135
  cmp    $0xe,%r9d
  jbe    L213
  mov    %edx,%edi
  add    %rbp,%rcx
  lea    0x0(%rbp,%r15,1),%r9
  xor    %eax,%eax
  shr    $0x4,%edi
  shl    $0x4,%rdi
  nopl   0x0(%rax)
L161:
  movdqu (%rcx,%rax,1),%xmm0
  movups %xmm0,(%r9,%rax,1)
  add    $0x10,%rax
  cmp    %rdi,%rax
  jne    L161
  mov    %edx,%eax
  and    $0xfffffff0,%eax
  add    %eax,%esi
  cmp    %eax,%edx
  je     L104
  sub    %eax,%edx
  lea    -0x1(%rdx),%edi
  cmp    $0x6,%edi
  jbe    L121
L32:
  mov    (%rcx,%rax,1),%rdi
  lea    0x0(%rbp,%r14,1),%rcx
  mov    %rdi,0x2(%rax,%rcx,1)
  mov    %edx,%eax
  and    $0xfffffff8,%eax
  add    %eax,%esi
  cmp    %edx,%eax
  je     L104
L121:
  lea    (%rbx,%rsi,1),%eax
  cltq
  movzbl -0x2(%rbp,%rax,1),%edx
  movslq %esi,%rax
  mov    %dl,0x0(%rbp,%rax,1)
  lea    0x1(%rsi),%eax
  cmp    %esi,%r12d
  jl     L104
  lea    (%rbx,%rax,1),%edx
  movslq %edx,%rdx
  movzbl -0x2(%rbp,%rdx,1),%ecx
  movslq %eax,%rdx
  mov    %cl,0x0(%rbp,%rdx,1)
  lea    0x2(%rsi),%edx
  cmp    %eax,%r12d
  jl     L104
  lea    (%rdx,%rbx,1),%eax
  cltq
  movzbl -0x2(%rbp,%rax,1),%ecx
  movslq %edx,%rax
  mov    %cl,0x0(%rbp,%rax,1)
  lea    0x3(%rsi),%eax
  cmp    %edx,%r12d
  jl     L104
  lea    (%rbx,%rax,1),%edx
  movslq %edx,%rdx
  movzbl -0x2(%rbp,%rdx,1),%ecx
  movslq %eax,%rdx
  mov    %cl,0x0(%rbp,%rdx,1)
  lea    0x4(%rsi),%edx
  cmp    %eax,%r12d
  jl     L104
  lea    (%rbx,%rdx,1),%eax
  cltq
  movzbl -0x2(%rbp,%rax,1),%ecx
  movslq %edx,%rax
  mov    %cl,0x0(%rbp,%rax,1)
  lea    0x5(%rsi),%eax
  cmp    %edx,%r12d
  jl     L104
  lea    (%rbx,%rax,1),%edx
  add    $0x6,%esi
  movslq %edx,%rdx
  movzbl -0x2(%rbp,%rdx,1),%ecx
  movslq %eax,%rdx
  mov    %cl,0x0(%rbp,%rdx,1)
  cmp    %eax,%r12d
  jl     L104
  lea    (%rbx,%rsi,1),%eax
  movslq %esi,%rsi
  cltq
  movzbl -0x2(%rbp,%rax,1),%eax
  mov    %al,0x0(%rbp,%rsi,1)
L104:
  add    $0x2,%r12d
  movslq %r12d,%rax
  movb   $0x0,0x0(%rbp,%rax,1)
L184:
  add    $0x30,%ebx
  mov    %bl,0x1(%rbp,%r14,1)
L206:
  add    $0x2,%r14
  add    $0x2,%r15
  cmp    %r14d,%r12d
  jg     L49
  mov    %rbp,%rdi
  call   <strlen@plt>
  mov    %r13,%rdi
  mov    %eax,%ebx
  call   <strlen@plt>
  cmp    %eax,%ebx
  jle    L241
L175:
  add    $0x8,%rsp
  mov    %r13,%rax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax)
L241:
  mov    %rbp,%r13
  jmp    L175
  nopl   (%rax)
L215:
  lea    -0x1(%r12),%eax
  cmp    %eax,%ecx
  jg     L87
  mov    %eax,%edx
  cltq
  sub    %ecx,%edx
  sub    %rdx,%rax
  add    $0x1,%rdx
  lea    0x0(%rbp,%rax,1),%rsi
  lea    0x1(%rbp,%rax,1),%rdi
  call   <memmove@plt>
  mov    $0x1,%r8d
L87:
  add    $0x1,%r12d
  jmp    L184
L135:
  lea    0x3(%rbp,%r14,1),%rcx
  add    %rbp,%rax
  add    %r9,%rcx
  nopl   0x0(%rax)
L277:
  movzbl -0x2(%rax,%rdi,1),%edx
  add    $0x1,%rax
  mov    %dl,-0x1(%rax)
  cmp    %rcx,%rax
  jne    L277
  jmp    L104
L213:
  xor    %eax,%eax
  add    %rbp,%rcx
  jmp    L32
```

assistant: ```c
char *sc(char str[]) {
  int i, j, k;
  int len;
  int count;
  char *old;
  len = strlen(str);
  old = malloc(sizeof(len + 1));
  strncpy(old, str, len);
  if (len < 1)
    return str;
  for (i = 0; i < len; i++, i++) {
    for (count = 1, j = i + 1; j < len + 1; j++)
      if (str[i] == str[j])
        count++;
      else {
        if (count == 1) {
          for (k = len - 1; k >= j; k--)
            str[k + 1] = str[k];
          len++;
        } else {
          for (k = i + 2; k < len - count + 2; k++)
            str[k] = str[k + count - 2];
          len = len - count + 2;
          str[len] = '\0';
        }
        str[i + 1] = '0' + count;
        break;
      }
  }
  if (strlen(str) > strlen(old))
    return old;
  else
    return str;
}
```