user: 请显示与下面列出的汇编代码相匹配的C语言实现:

```asm
<main>:
  endbr64
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    $0x10,%edi
  call   <malloc@plt>
  mov    %rax,%r13
  movq   $0x0,(%rax)
  movq   $0x0,0x8(%rax)
  jmp    L169
L64:
  cmpq   $0x0,0x8(%rbx)
  je     L16
L169:
  mov    $0x0,%eax
  call   <__VERIFIER_nondet_int@plt>
  test   %eax,%eax
  je     L121
  mov    0x0(%r13),%rbp
  mov    %r13,%rbx
  test   %rbp,%rbp
  je     L124
L127:
  mov    0x8(%rbx),%r12
  test   %r12,%r12
  je     L85
  mov    $0x0,%eax
  call   <__VERIFIER_nondet_int@plt>
  test   %eax,%eax
  mov    %r12,%rbx
  cmovne %rbp,%rbx
  mov    (%rbx),%rbp
  test   %rbp,%rbp
  jne    L127
L124:
  mov    $0x0,%eax
  call   <__VERIFIER_nondet_int@plt>
  test   %eax,%eax
  je     L64
  mov    $0x10,%edi
  call   <malloc@plt>
  mov    %rax,(%rbx)
  movq   $0x0,(%rax)
  mov    (%rbx),%rax
  movq   $0x0,0x8(%rax)
  jmp    L64
L121:
  mov    $0x10,%edi
  call   <malloc@plt>
  mov    %rax,%rbx
  movq   $0x0,(%rax)
  mov    %r13,0x8(%rax)
  jmp    L25
L53:
  mov    0x8(%rbp),%r13
  test   %r13,%r13
  je     L165
  mov    %r14,%r12
L46:
  mov    $0x10,%edi
  call   <malloc@plt>
  mov    %rax,%rbx
  mov    %r12,(%rax)
  mov    %r13,0x8(%rax)
  mov    %rbp,%rdi
  call   <free@plt>
L25:
  mov    (%rbx),%r14
  mov    0x8(%rbx),%rbp
  mov    %rbx,%rdi
  call   <free@plt>
  cmpq   $0x0,0x0(%rbp)
  je     L53
  mov    $0x10,%edi
  call   <malloc@plt>
  mov    %rax,%r12
  mov    %r14,(%rax)
  mov    0x0(%rbp),%rax
  mov    %rax,0x8(%r12)
  mov    0x8(%rbp),%r13
  test   %r13,%r13
  jne    L46
  mov    %rbp,%rdi
  call   <free@plt>
  mov    %r12,%rbx
  jmp    L25
L165:
  mov    %rbp,%rdi
  call   <free@plt>
  test   %r14,%r14
  jne    L136
  mov    $0x0,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
L136:
  mov    %r14,%rbx
  jmp    L25
L85:
  test   %rbp,%rbp
  je     L124
L16:
  mov    $0x0,%eax
  call   <__VERIFIER_nondet_int@plt>
  test   %eax,%eax
  je     L169
  mov    $0x10,%edi
  call   <malloc@plt>
  mov    %rax,0x8(%rbx)
  movq   $0x0,(%rax)
  mov    0x8(%rbx),%rax
  movq   $0x0,0x8(%rax)
  jmp    L169
```

assistant: ```c
int main() {
  struct TreeNode {
    struct TreeNode *left;
    struct TreeNode *right;
  };
  struct StackItem {
    struct StackItem *next;
    struct TreeNode *node;
  };
  struct TreeNode *root = malloc(sizeof(*root)), *n;
  root->left = ((void *)0);
  root->right = ((void *)0);
  while (__VERIFIER_nondet_int()) {
    n = root;
    while (n->left && n->right) {
      if (__VERIFIER_nondet_int())
        n = n->left;
      else
        n = n->right;
    }
    if (!n->left && __VERIFIER_nondet_int()) {
      n->left = malloc(sizeof(*n));
      n->left->left = ((void *)0);
      n->left->right = ((void *)0);
    }
    if (!n->right && __VERIFIER_nondet_int()) {
      n->right = malloc(sizeof(*n));
      n->right->left = ((void *)0);
      n->right->right = ((void *)0);
    }
  }
  n = ((void *)0);
  struct StackItem *s = malloc(sizeof(*s)), *st;
  s->next = ((void *)0);
  s->node = root;
  while (s != ((void *)0)) {
    st = s;
    s = s->next;
    n = st->node;
    free(st);
    if (n->left) {
      st = malloc(sizeof(*st));
      st->next = s;
      st->node = n->left;
      s = st;
    }
    if (n->right) {
      st = malloc(sizeof(*st));
      st->next = s;
      st->node = n->right;
      s = st;
    }
    free(n);
  }
  return 0;
}
```