vector元素为自定义数据时如何进行排序

方法一：在结构体中重载< 、>运算符，调用STL的sort（）函数

#include "stdafx.h"

#include <vector>

#include <algorithm>

#include <iostream>

using namespace std;

class MYSTRUCT

{

public:

int id;

int nums;

vector<int> vec;

MYSTRUCT()

{

id=numeric_limits<int>::max();

nums=0;

vec.resize(0);

}

//重载==

bool operator==( const MYSTRUCT& objstruct) const

{

return objstruct.id==id;

}

//重载<

bool operator<(const MYSTRUCT& objstruct) const

{

return id<objstruct.id;

}

//重载>

bool operator>(const MYSTRUCT& objstuct) const

{

return id>objstuct.id;

}

};

int _tmain(int argc, _TCHAR* argv[])

{

vector<MYSTRUCT> structs;

for(int i=0;i<9;i++)

{

MYSTRUCT myStruct;

//myStruct.id=i;

myStruct.nums=i;

structs.push_back(myStruct);

}

structs[0].id=9;

structs[1].id=1;

structs[2].id=7;

structs[3].id=3;

structs[4].id=8;

structs[5].id=2;

structs[6].id=6;

structs[7].id=0;

structs[8].id=10;

sort(structs.begin(),structs.end());

for(vector<MYSTRUCT>::iterator it=structs.begin();it!=structs.end();++it)

{

std::cout<<it->id<<endl;

}

return 0;

}


方法二：
单独定义比较函数，调用STL的sort（）函数，不修改结构体

#include "stdafx.h"

#include <vector>

#include <algorithm>

#include <iostream>

using namespace std;

class MYSTRUCT

{

public:

int id;

int nums;

vector<int> vec;

MYSTRUCT()

{

id=numeric_limits<int>::max();

nums=0;

vec.resize(0);

}

// //重载==

// bool operator==( const MYSTRUCT& objstruct) const

// {

// return objstruct.id==id;

// }

//

// //重载<

// bool operator<(const MYSTRUCT& objstruct) const

// {

// return id<objstruct.id;

// }

//

// //重载>

// bool operator>(const MYSTRUCT& objstuct) const

// {

// return id>objstuct.id;

// }

};

bool lessCompare(const MYSTRUCT& obj1,const MYSTRUCT& obj2)

{

return obj1.id<obj2.id;

}

bool greaterCompare(const MYSTRUCT& obj1,const MYSTRUCT& obj2)

{

return obj1.id>obj2.id;

}

int _tmain(int argc, _TCHAR* argv[])

{

vector<MYSTRUCT> structs;

for(int i=0;i<9;i++)

{

MYSTRUCT myStruct;

//myStruct.id=i;

myStruct.nums=i;

structs.push_back(myStruct);

}

structs[0].id=9;

structs[1].id=1;

structs[2].id=7;

structs[3].id=3;

structs[4].id=8;

structs[5].id=2;

structs[6].id=6;

structs[7].id=0;

structs[8].id=10;

sort(structs.begin(),structs.end(),lessCompare);

for(vector<MYSTRUCT>::iterator it=structs.begin();it!=structs.end();++it)

{

std::cout<<it->id<<endl;

}

return 0;

}