user: 请从给定的汇编指令推导出C源代码：

```asm
<main>:
  endbr64
  sub    $0x28,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0x18(%rsp)
  xor    %eax,%eax
  lea    D43(%rip),%rdi
  call   <printf@plt>
  lea    0xc(%rsp),%rsi
  lea    D27(%rip),%rdi
  mov    $0x0,%eax
  call   <scanf@plt>
  lea    D41(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  lea    0x10(%rsp),%rsi
  lea    D101(%rip),%rdi
  mov    $0x0,%eax
  call   <scanf@plt>
  mov    0x10(%rsp),%eax
  cmp    $0x1,%eax
  je     L84
  cmp    $0x2,%eax
  je     L20
  lea    D80(%rip),%rdi
  call   <puts@plt>
L81:
  mov    0x18(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L78
  mov    $0x0,%eax
  add    $0x28,%rsp
  ret
L84:
  movss  0xc(%rsp),%xmm1
  movaps %xmm1,%xmm0
  mulss  D93(%rip),%xmm0
  divss  D68(%rip),%xmm0
  subss  %xmm0,%xmm1
  cvtss2sd %xmm0,%xmm0
  cvtss2sd %xmm1,%xmm1
  lea    D129(%rip),%rdi
  mov    $0x2,%eax
  call   <printf@plt>
  jmp    L81
L20:
  lea    D87(%rip),%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  lea    0x14(%rsp),%rsi
  lea    D101(%rip),%rdi
  mov    $0x0,%eax
  call   <scanf@plt>
  mov    0x14(%rsp),%eax
  cmp    $0x2,%eax
  je     L4
  cmp    $0x3,%eax
  je     L76
  lea    D1(%rip),%rdi
  call   <puts@plt>
  jmp    L81
L4:
  movss  D153(%rip),%xmm0
  mulss  0xc(%rsp),%xmm0
  cvtss2sd %xmm0,%xmm0
  lea    D52(%rip),%rdi
  mov    $0x1,%eax
  call   <printf@plt>
  jmp    L81
L76:
  movss  0xc(%rsp),%xmm1
  movaps %xmm1,%xmm0
  mulss  D93(%rip),%xmm0
  divss  D68(%rip),%xmm0
  addss  %xmm0,%xmm1
  movaps %xmm1,%xmm2
  divss  D108(%rip),%xmm2
  cvtss2sd %xmm0,%xmm0
  cvtss2sd %xmm2,%xmm2
  cvtss2sd %xmm1,%xmm1
  lea    D55(%rip),%rdi
  call   <printf@plt>
  jmp    L81
L78:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: parse_data
arguments: tag: D43
data_type: string
name: parse_data
arguments: tag: D27
data_type: string
name: parse_data
arguments: tag: D41
data_type: string
name: parse_data
arguments: tag: D101
data_type: string
name: parse_data
arguments: tag: D80
data_type: string
name: parse_data
arguments: tag: D93
data_type: byte[4]
name: parse_data
arguments: tag: D68
data_type: byte[4]
name: parse_data
arguments: tag: D129
data_type: string
name: parse_data
arguments: tag: D87
data_type: string
name: parse_data
arguments: tag: D1
data_type: string
name: parse_data
arguments: tag: D153
data_type: byte[4]
name: parse_data
arguments: tag: D52
data_type: string
name: parse_data
arguments: tag: D108
data_type: byte[4]
name: parse_data
arguments: tag: D55
data_type: string

tool: D43: 
Qual o valor da compra
-->

tool: D27: %f

tool: D41: 
Qual a opcao de pagamento

1 - A Vista
2 - A Prazo

-->

tool: D101: %d

tool: D80: 
Opcao de pagamento invalida


tool: {"D93": [0x00,0x00,0x20,0x41]}

tool: {"D68": [0x00,0x00,0xc8,0x42]}

tool: D129: 
Voce ganhou um desconto de R$%.2f
Valor a pagar %.2f



tool: D87: 
Numero de Parcelas (2 ou 3):

-->

tool: D1: 
Numero de Parcelas invalido


tool: {"D153": [0x00,0x00,0x00,0x3f]}

tool: D52: 
Valor de cada parcela R$%.2f



tool: {"D108": [0x00,0x00,0x40,0x40]}

tool: D55: 
Valor do acrecimo R$%.2f
Valor a Pagar R$%.2f
Valor de cada parcela R$%.2f



assistant: ```c
int main() {
  float vlr_compra, a_pag, parc, desc, acres;
  int op_pag, n_parc;
  printf("\nQual o valor da compra\n-->");
  scanf("%f", &vlr_compra);
  printf("\nQual a opcao de pagamento\n\n1 - A Vista\n2 - A Prazo\n\n-->");
  scanf("%d", &op_pag);
  if (op_pag == 1) {
    desc = vlr_compra * 10 / 100;
    a_pag = vlr_compra - desc;
    printf("\nVoce ganhou um desconto de R$%.2f\nValor a pagar %.2f\n\n", desc, a_pag);
  } else {
    if (op_pag == 2) {
      printf("\nNumero de Parcelas (2 ou 3):\n\n-->");
      scanf("%d", &n_parc);
      if (n_parc == 2) {
        parc = vlr_compra / 2;
        printf("\nValor de cada parcela R$%.2f\n\n", parc);
      } else {
        if (n_parc == 3) {
          acres = vlr_compra * 10 / 100;
          a_pag = vlr_compra + acres;
          parc = a_pag / 3;
          printf("\nValor do acrecimo R$%.2f\nValor a Pagar R$%.2f\nValor de cada parcela R$%.2f\n\n", acres, a_pag, parc);
        } else {
          printf("\nNumero de Parcelas invalido\n\n");
        }
      }
    } else {
      printf("\nOpcao de pagamento invalida\n\n");
    }
  }
  return 0;
}
```