user: 提供的汇编代码用C语言表示会是什么样子：

```asm
<permute>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  mov    %edi,%ebp
  mov    %esi,0xc(%rsp)
  mov    %rdx,%r12
  mov    %fs:0x28,%rax
  mov    %rax,0x28(%rsp)
  xor    %eax,%eax
  mov    (%rdx),%rax
  mov    %rax,0x18(%rsp)
  mov    (%rcx),%rdx
  mov    %rdx,0x20(%rsp)
  test   %rax,%rax
  je     L4
L73:
  cmp    $0x1,%ebp
  je     L29
  test   %ebp,%ebp
  jle    L20
  mov    %ebp,%eax
  shr    $0x1f,%eax
  lea    0x0(%rbp,%rax,1),%r13d
  and    $0x1,%r13d
  sub    %eax,%r13d
  movslq %ebp,%rax
  lea    -0x4(,%rax,4),%r14
  mov    %ebp,%r12d
  shl    $0x2,%r12
  mov    $0x0,%ebx
  lea    0x20(%rsp),%r15
  jmp    L2
L4:
  mov    %rcx,%rbx
  call   <factorial@plt>
  lea    0x8(,%rax,8),%edi
  call   <malloc@plt>
  mov    %rax,0x18(%rsp)
  mov    %rax,(%r12)
  movq   $0x0,(%rax)
  lea    0x0(,%rbp,4),%edi
  call   <malloc@plt>
  mov    %rax,0x20(%rsp)
  test   %ebp,%ebp
  jle    L115
  mov    %ebp,%ecx
  mov    $0x0,%edx
L30:
  mov    %edx,(%rax,%rdx,4)
  add    $0x1,%rdx
  cmp    %rcx,%rdx
  jne    L30
L115:
  mov    %rax,(%rbx)
  mov    %ebp,0xc(%rsp)
  jmp    L73
L29:
  mov    0x18(%rsp),%rsi
  lea    0x8(%rsi),%rdx
  mov    $0x1,%eax
  cmpq   $0x0,(%rsi)
  je     L104
L24:
  mov    %rdx,%rbx
  mov    %rax,%rcx
  add    $0x1,%rax
  add    $0x8,%rdx
  cmpq   $0x0,(%rbx)
  jne    L24
L93:
  movq   $0x0,0x8(%rsi,%rcx,8)
  mov    0xc(%rsp),%ebp
  shl    $0x2,%ebp
  mov    %ebp,%edi
  call   <malloc@plt>
  mov    %rax,%rdi
  mov    %rax,(%rbx)
  mov    %ebp,%edx
  mov    0x20(%rsp),%rsi
  call   <memcpy@plt>
L20:
  mov    0x28(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L23
  add    $0x38,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L104:
  mov    %rsi,%rbx
  mov    $0x0,%ecx
  jmp    L93
L91:
  mov    0x20(%rsp),%rax
  lea    (%rax,%rbx,1),%rdx
  mov    (%rdx),%ecx
  add    %r14,%rax
  mov    (%rax),%esi
  mov    %esi,(%rdx)
  mov    %ecx,(%rax)
L49:
  add    $0x4,%rbx
  cmp    %r12,%rbx
  je     L20
L2:
  lea    0x18(%rsp),%rdx
  lea    -0x1(%rbp),%edi
  mov    %r15,%rcx
  mov    0xc(%rsp),%esi
  call   <permute>
  cmp    $0x1,%r13d
  jne    L91
  mov    0x20(%rsp),%rax
  mov    (%rax),%ecx
  lea    (%rax,%r14,1),%rdx
  mov    (%rdx),%esi
  mov    %esi,(%rax)
  mov    %ecx,(%rdx)
  jmp    L49
L23:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
void permute(int n, int m, int ***perms_p, int **a_p) {
  int i;
  int **perms = *perms_p;
  int *a = *a_p;
  if (perms == NULL) {
    perms = malloc((factorial((unsigned int)n) + 1) * sizeof(int *));
    *perms_p = perms;
    perms[0] = NULL;
    a = malloc(n * sizeof(int));
    for (i = 0; i < n; i++)
      a[i] = i;
    *a_p = a;
    m = n;
  }
  if (n == 1) {
    for (i = 0;; i++) {
      if (perms[i] == NULL) {
        perms[i + 1] = NULL;
        perms[i] = malloc(m * sizeof(int));
        memcpy(perms[i], a, m * sizeof(int));
        break;
      }
    }
  } else {
    for (i = 0; i < n; i++) {
      permute(n - 1, m, &perms, &a);
      int swap;
      if (n % 2 == 1) {
        swap = a[0];
        a[0] = a[n - 1];
        a[n - 1] = swap;
      } else {
        swap = a[i];
        a[i] = a[n - 1];
        a[n - 1] = swap;
      }
    }
  }
}
```