如何对列表进行排序 [英] how to sort the list

问题描述

嗨.
我们有一个班级的名单.
如何通过X作为变量对它进行排序?(X是Class的成员)

Hi.
we have a list of one class.
how to sort it by a variable as X ?( X is member of Class)

推荐答案

A)是否需要编写排序算法来对类成员变量?

或

B)您是否想知道如何使用类成员变量对STL中的类进行排序?


无论哪种情况，我都建议写一个函子来帮助您对类成员进行比较:

A) Do you need to write a sorting algorithm to do the sorting on the class member variable?

OR

B) Do you want to know how to sort the class in STL with a class member variable?


For either case, I would recommend writing a functor to help with the comparisons on your class member:

struct CompareYourClassMemberXLess
{
  bool operator()(const YourClass &lhs, const YourClass &rhs)
  {
    // If they reference the same object, return false.
    // This will create a strict weak ordering.
    if (&lhs == &rhs)
      return false;

    return lhs.GetX() < rhs.GetX();
  }
};

// The declaration for the call to "GetX() const" will need to be declared with const.

在排序之前，请创建函子的实例:

Create an instance of your functor before you sort:

CompareYourClassMemberXLess CmpXLess;

现在，在排序算法中，当您要比较两个值时，可以像调用函数一样调用变量CmpXLess来确定其在搜索顺序中的位置.

Now in your sort algorithm, when you want to compare the two values in, you can call the varible CmpXLess like a function to determine where it fits in the search order.

YourClass a;
YourClass b;

CmpXLess(a,b);

对于STL，请像这样使用它:

for STL use it like this:

std::sort(a.begin(), b.begin(), CompareYourClassMemberXLess());

顺便说一句，随意将令人讨厌的长名称更改为您的程序中有意义的名称.名称不会更改功能.

BTW, feel free to change the obnoxiously long names to something that makes sense in your program. The names will not change the functionality.

尝试使用此方法肯定会对您有所帮助...


http://www.dotnetperls.com/sort-list [

Try this will definitely help you...


http://www.dotnetperls.com/sort-list[^]

请参阅:
http://msdn.microsoft.com/en-us/library/b0zbh7b6.aspx#Y0 [^ ]
http://msdn.microsoft.com/en -us/library/system.collections.arraylist.sort(v = vs.71).aspx [ http://www.cplusplus.com/reference/stl/list/sort/ [ ^ ]

它会为您提供帮助. :)

-MKB

See :
http://msdn.microsoft.com/en-us/library/b0zbh7b6.aspx#Y0[^]
http://msdn.microsoft.com/en-us/library/system.collections.arraylist.sort(v=vs.71).aspx[^]
http://www.cplusplus.com/reference/stl/list/sort/[^]

It will help you. :)

-MKB

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