std :: priority_queue包含我自己的类

问题描述

让我介绍一下我的课程:

Let me introduce my class:

#include <tuple>
#include <queue>
#include <initializer_list>

template <typename HType>
class Huffman {

    class TreeOfLetters {
        HType Value;
        char Letter;
        TreeOfLetters *Root = nullptr;
        TreeOfLetters *Left = nullptr;
        TreeOfLetters *Right = nullptr;

        TreeOfLetters(HType _Value, char _Letter) : Value(_Value), Letter(_Letter) {
        };


    };

     auto compare = [](const TreeOfLetters &a,const TreeOfLetters &b){
    return a.Value < b.Value;};

    std::priority_queue(TreeOfLetters, std::set<TreeOfLetters>, compare);

public:
    Huffman(std::initializer_list<HType> _Values, std::initializer_list<char> _Chars);
    Huffman(const Huffman& orig) = delete;


};

我想要实现的是在std :: priority_queue中存储指向Trees的指针，使得在顶部将是值最高的指针.

What I want to achieve is to store pointers to Trees in the std::priority_queue in such a way that on top will be the one which the value is the highest.

我知道我可以随心所欲地得到一个容器，然后对其进行排序，但是我想使用std :: priority_queue，它会自动完成它.

I know that I could get a container whatever I like and then sort it but I want to use the std::priority_queue which will do it automatically.

由于我不太熟悉c ++ 11功能，因此我收到一些错误，非常感谢您为摆脱这些错误所提供的帮助.

Since I am not very familiar with c++11 features I am receiving some errors and I would highly appreciate your help with getting rid of them.

首先，我不确定我的lambda是否正确，这就是为什么我希望一些专家确认我的approuch是否正确.

First of all I am not sure if my lambda is correct that is why I want some experts to cofirm whether my approuch is correct or not.

我收到的警告:

无法解析标识符比较.

无法解析标识符值.

非常感谢Piotr和Thoran的帮助，我确实使<运算符，所以我将这些行添加到我的课程中

Big thanks to Piotr and Thoran for their help I did overload the < operator so I add these lines to my class

bool operator<(const TreeOfLetters &a,const TreeOfLetters &b)
 {
   return a.Value < b.Value;
 } 

我仍然收到来自下一行的错误，我非常感谢您的帮助，可以帮助我解决问题.

I am still receiving an error from a following line I will highly appreciate an approuch what will help me to solve it.

 std::priority_queue <TreeOfLetters, std::vector<TreeOfLetters>, Compare> queue;

推荐答案

您对Compare函数和队列的定义看起来很奇怪.你的意思是这样吗?这在Visual C ++中对我有用

Your definition of the Compare function and the queue looks strange. Did you mean something like this? This works for me in Visual C++

template <typename HType>
class Huffman {

    class TreeOfLetters {
        HType Value;
        char Letter;
        TreeOfLetters *Root;
        TreeOfLetters *Left;
        TreeOfLetters *Right;

        TreeOfLetters(HType _Value, char _Letter) : Value(_Value), Letter(_Letter), Root(nullptr), Left(nullptr), Right(nullptr){
        };


    };

    struct Compare
    {
        bool operator()(const TreeOfLetters& a, const TreeOfLetters& b)
        {
            return a.Value < b.value;
        }
    };

    std::priority_queue<TreeOfLetters, std::vector<TreeOfLetters>, Compare> queue;

public:
    Huffman(std::initializer_list<HType> _Values, std::initializer_list<char> _Chars) : queue(Compare()) {}
    Huffman(const Huffman& orig) = delete;

};

或者您可以将比较实现为lambda

or you can implement the comparison as a lambda

std::priority_queue<TreeOfLetters, std::vector<TreeOfLetters>, [](const TreeOfLetters& a, const TreeOfLetters& b){return a.Value < b.value;}> queue;

您应该使用某些特征将HType限制为基本值，否则必须为要使用的实际HType实现>"运算符.

You should restrict your HType to basic values using some traits, or else you have to implement the ">" operator for the actual HType you want to use.

另请参见上面的@Piotr Skotnicki评论.

See also @Piotr Skotnicki comment above.

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