(C++) 在堆栈中使用向量作为包装器

(C++) using a vector as a wrapper in a stack

编辑:回答了原始问题。不过,相关问题并不像是在制作一个新的 post。为什么我无法使用堆栈的 push() 和 pop() 函数调用?以下是错误:

HCTree.cpp:65:16: error: no matching member function for call to 'push'
  encoding.push(0);
  ~~~~~~~~~^~~~
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/stack:197:10: note: 
  candidate function not viable: 'this' argument has type 'const stack<int,
  std::vector<int> >', but method is not marked const
void push(value_type&& __v) {c.push_back(_VSTD::move(__v));}
     ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/stack:194:10: note: 
  candidate function not viable: 'this' argument has type 'const stack<int,
  std::vector<int> >', but method is not marked const
void push(const value_type& __v) {c.push_back(__v);}
     ^
HCTree.cpp:67:16: error: no matching member function for call to 'push'
  encoding.push(1);
  ~~~~~~~~~^~~~
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/stack:197:10: note: 
  candidate function not viable: 'this' argument has type 'const stack<int,
  std::vector<int> >', but method is not marked const
void push(value_type&& __v) {c.push_back(_VSTD::move(__v));}
     ^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/stack:194:10: note: 
  candidate function not viable: 'this' argument has type 'const stack<int,
  std::vector<int> >', but method is not marked const
void push(const value_type& __v) {c.push_back(__v);}
     ^
HCTree.cpp:73:16: error: member function 'pop' not viable: 'this' argument has type 'const
  stack<int, std::vector<int> >', but function is not marked const
  out.writeBit(encoding.pop());
           ^~~~~~~~
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/stack:206:10: note: 
  'pop' declared here
void pop() {c.pop_back();}
     ^

代码:

void HCTree::encode(byte symbol, BitOutputStream& out) const
{

  HCNode* temp;
  temp = leaves[symbol];//store leaf node containing symbol into temp
  /* traverse to the top of the tree */
  while(temp->p != NULL)
  {
    /* record path we take to parent into a stack */
    if(temp == temp->p->c0)//if temp is the c0 child
      encoding.push(0);
    else//temp is the c1 child
      encoding.push(1);

    temp = temp->p;//move up to temp's parent and repeat
  }

   /* write bits to buffer */
   out.writeBit(encoding.pop());


}

来自HCTree.hpp的相关行:

    stack<int,std::vector<int>> encoding;

是否有关于使用向量阻止我使用 push() 和 pop() 函数调用的问题?

----原文post----: 我正在尝试创建一个堆栈,它使用向量作为包装器在 C++ 中存储整数,就像在此处看到的示例中所做的那样:http://www.cplusplus.com/reference/stack/stack/stack/

我需要一个存储整数的堆栈,所以我有代码:

std::vector<int> wrapper;
stack<int,std::vector<int>> encoding (wrapper);

我收到以下错误:

Compiling: compress.cpp -> build/compress.o
In file included from compress.cpp:19:
./HCTree.hpp:35:43: error: unknown type name 'wrapper'
stack<int,std::vector<int>> encoding (wrapper);

如何修复我的实现?我需要创建一个最初的 堆栈来在我回溯二叉树时将 1 和 0 压入,以便稍后弹出以重建所采用的路径。

默认为空堆栈。您只需要:

#include <stack>
#include <vector>

std::stack<int, std::vector<int> > encoding;

此外,cplusplus.com 不是一个很好的来源。它有更多的广告和更少的编辑。避开它。

I need to create an initially empty stack to push 1's and 0's onto as I backtrace a binary tree in order to later pop off to rebuild the path that was taken.

为什么不 std::stack< bool, std::vector< bool > >?请注意 std::vector< bool > 具有最佳存储特性。


第二个问题

(请不要添加问题。打开新问题是免费的。)

您不能在标记为 const 的成员函数内更改 encoding,因为该上下文使数据成员的行为与 const 相同。有几种解决方案:

  1. encode 函数不是 const,因为它有意义地改变了 HCTree 对象的状态。
  2. 不要让 encoding 成为 HCTree 的成员。将它放在其他一些对象中或要求它由用户提供。
  3. 声明 encodingmutable。这似乎不合适。 mutable 成员的状态通常不应该被观察到,除了性能提升等副作用。