user: 请将这段汇编代码片段转换成等效的C代码:

```asm
<combine>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x50,%rsp
  mov    %edi,-0x34(%rbp)
  mov    %esi,-0x38(%rbp)
  mov    %rdx,-0x40(%rbp)
  mov    %rcx,-0x48(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x8(%rbp)
  xor    %eax,%eax
  movl   $0x1,-0x20(%rbp)
  movl   $0x1,-0x1c(%rbp)
  mov    -0x34(%rbp),%eax
  cmp    -0x38(%rbp),%eax
  jl     L5
  cmpl   $0x0,-0x34(%rbp)
  jle    L5
  cmpl   $0x0,-0x38(%rbp)
  jg     L55
L5:
  mov    -0x48(%rbp),%rax
  movl   $0x0,(%rax)
  mov    $0x0,%edi
  call   <malloc@plt>
  mov    %rax,%rdx
  mov    -0x40(%rbp),%rax
  mov    %rdx,(%rax)
  mov    $0x0,%edi
  call   <malloc@plt>
  jmp    L91
L55:
  movl   $0x0,-0x24(%rbp)
  jmp    L83
L20:
  mov    -0x24(%rbp),%ecx
  mov    -0x34(%rbp),%eax
  sub    %ecx,%eax
  mov    %eax,%edx
  mov    -0x20(%rbp),%eax
  imul   %edx,%eax
  mov    %eax,-0x20(%rbp)
  mov    -0x24(%rbp),%ecx
  mov    -0x38(%rbp),%eax
  sub    %ecx,%eax
  mov    %eax,%edx
  mov    -0x1c(%rbp),%eax
  imul   %edx,%eax
  mov    %eax,-0x1c(%rbp)
  mov    -0x24(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,-0x24(%rbp)
L83:
  mov    -0x24(%rbp),%eax
  cmp    %eax,-0x38(%rbp)
  jg     L20
  mov    -0x20(%rbp),%eax
  cltd
  idivl  -0x1c(%rbp)
  mov    %eax,-0x20(%rbp)
  mov    -0x48(%rbp),%rax
  mov    -0x20(%rbp),%edx
  mov    %edx,(%rax)
  mov    -0x20(%rbp),%eax
  cltq
  shl    $0x3,%eax
  mov    %eax,%edi
  call   <malloc@plt>
  mov    %rax,-0x18(%rbp)
  movl   $0x0,-0x24(%rbp)
  jmp    L4
L82:
  mov    -0x38(%rbp),%eax
  cltq
  shl    $0x2,%eax
  mov    %eax,%edi
  call   <malloc@plt>
  mov    -0x24(%rbp),%edx
  movslq %edx,%rdx
  lea    0x0(,%rdx,8),%rcx
  mov    -0x18(%rbp),%rdx
  add    %rcx,%rdx
  mov    %rax,(%rdx)
  mov    -0x24(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,-0x24(%rbp)
L4:
  mov    -0x24(%rbp),%eax
  cmp    %eax,-0x20(%rbp)
  jg     L82
  mov    -0x20(%rbp),%eax
  cltq
  shl    $0x2,%eax
  mov    %eax,%edi
  call   <malloc@plt>
  mov    %rax,%rdx
  mov    -0x40(%rbp),%rax
  mov    %rdx,(%rax)
  movl   $0x0,-0x24(%rbp)
  jmp    L21
L73:
  mov    -0x40(%rbp),%rax
  mov    (%rax),%rdx
  mov    -0x24(%rbp),%eax
  cltq
  shl    $0x2,%rax
  add    %rax,%rdx
  mov    -0x38(%rbp),%eax
  mov    %eax,(%rdx)
  mov    -0x24(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,-0x24(%rbp)
L21:
  mov    -0x24(%rbp),%eax
  cmp    %eax,-0x20(%rbp)
  jg     L73
  mov    -0x38(%rbp),%eax
  cltq
  shl    $0x2,%eax
  mov    %eax,%edi
  call   <malloc@plt>
  mov    %rax,-0x10(%rbp)
  movl   $0x0,-0x24(%rbp)
  mov    -0x38(%rbp),%edi
  mov    -0x10(%rbp),%rcx
  lea    -0x24(%rbp),%rdx
  mov    -0x18(%rbp),%rsi
  mov    -0x34(%rbp),%eax
  mov    $0x0,%r9d
  mov    %edi,%r8d
  mov    %eax,%edi
  call   <push@plt>
  mov    -0x18(%rbp),%rax
L91:
  mov    -0x8(%rbp),%rdx
  sub    %fs:0x28,%rdx
  je     L59
  call   <__stack_chk_fail@plt>
L59:
  leave
  ret
```

assistant: ```c
int **combine(int n, int k, int **columnSizes, int *returnSize) {
  int **ret, i, *dat;
  int p = 1, q = 1;
  if (n < k || n <= 0 || k <= 0) {
    *returnSize = 0;
    *columnSizes = (int *)malloc(0);
    return (int **)malloc(0);
  }
  for (i = 0; i < k; ++i) {
    p *= n - i;
    q *= k - i;
  }
  *returnSize = p /= q;
  ret = (int **)malloc(sizeof(int *) * p);
  for (i = 0; i < p; ++i)
    ret[i] = (int *)malloc(sizeof(int) * k);
  *columnSizes = (int *)malloc(p * sizeof(int));
  for (i = 0; i < p; ++i)
    (*columnSizes)[i] = k;
  dat = (int *)malloc(sizeof(int) * k);
  i = 0;
  push(n, ret, &i, dat, k, 0);
  return ret;
}
```