c++利用stl set_difference对车辆进出区域进行判定

#include  

#include 

#include 

#include 

usingnamespacestd; 

struct_AREA_VECTOR_STRUCT

{

  intnAreaType;//区域类型

  intnAreaID;//区域ID

};

voidCtestDlg::OnBnClickedButton2()

{

  vector<_area_vector_struct>structAreaHistory;//车辆上一次所在区域

  vector<_area_vector_struct>structAreaNow;//车辆本次所在区域

  vector<_area_vector_struct>OutStructAreaVector;//输出区域

  _AREA_VECTOR_STRUCT structVehicle;

  //模拟上一次车辆所在的区域集合

  structVehicle.nAreaType = 2;

  structVehicle.nAreaID = 0x45;

  structAreaHistory.push_back(structVehicle);

  structVehicle.nAreaID = 0x7A;

  structAreaHistory.push_back(structVehicle);

  structVehicle.nAreaID = 0x88;

  structAreaHistory.push_back(structVehicle);

  structVehicle.nAreaType = 3;

  structVehicle.nAreaID = 0x55;

  structAreaHistory.push_back(structVehicle);

  structVehicle.nAreaID = 0x88;

  structAreaHistory.push_back(structVehicle);

  //模拟本次车辆所在的区域集合

  structVehicle.nAreaType = 2;

  structVehicle.nAreaID = 0x88;

  structAreaNow.push_back(structVehicle);

  structVehicle.nAreaID = 0x45;

  structAreaNow.push_back(structVehicle);

  structVehicle.nAreaID = 0x11;

  structAreaNow.push_back(structVehicle);

  structVehicle.nAreaType = 3;

  structVehicle.nAreaID = 0x55;

  structAreaNow.push_back(structVehicle);

  //排序，先按区域类型排序，再按区域ID排序

  sort(structAreaHistory.begin(),  structAreaHistory.end(),[] (_AREA_VECTOR_STRUCT structArea1,  _AREA_VECTOR_STRUCT structArea2)->bool

  {

    if(structArea1.nAreaType != structArea2.nAreaType)

      returnstructArea1.nAreaType < structArea2.nAreaType;

    else

      returnstructArea1.nAreaID < structArea2.nAreaID;

  });

  sort(structAreaNow.begin(), structAreaNow.end(),[] (_AREA_VECTOR_STRUCT structArea1, _AREA_VECTOR_STRUCT structArea2)->bool

  {

    if(structArea1.nAreaType != structArea2.nAreaType)

      returnstructArea1.nAreaType < structArea2.nAreaType;

    else

      returnstructArea1.nAreaID < structArea2.nAreaID;

  });

  inta = 0;

  //求差，结果为离开区域的集合（出区域）

  set_difference(structAreaHistory.begin(),  structAreaHistory.end(), structAreaNow.begin(), structAreaNow.end(),  back_inserter(OutStructAreaVector),

    [](_AREA_VECTOR_STRUCT structArea1, _AREA_VECTOR_STRUCT structArea2)->bool

  {

    if(structArea1.nAreaType != structArea2.nAreaType)

      returnstructArea1.nAreaType < structArea2.nAreaType;

    else

      returnstructArea1.nAreaID < structArea2.nAreaID;

  });

  if(OutStructAreaVector.size() != 0)

  {

    TRACE("出");

  }

  OutStructAreaVector.clear();//先清空

  //反过来求差，结果为新进入的区域集合（新进区域）

  set_difference(structAreaNow.begin(),  structAreaNow.end(), structAreaHistory.begin(),  structAreaHistory.end(), back_inserter(OutStructAreaVector),

    [](_AREA_VECTOR_STRUCT structArea1, _AREA_VECTOR_STRUCT structArea2)->bool

  {

    if(structArea1.nAreaType != structArea2.nAreaType)

      returnstructArea1.nAreaType < structArea2.nAreaType;

    else

      returnstructArea1.nAreaID < structArea2.nAreaID;

  });

  if(OutStructAreaVector.size() != 0)

  {

    TRACE("重新进");

  }

}