STL自定义排序（sort）和自定义去重（unique）

• 自定义比较函数

#include<iostream>
#include<algorithm>
#include<cstring>
#include<vector>
using namespace std;
class Link
{
public:
	int a;
	int b;
	string str;
};

int main()
{
	Link l1;
	l1.a = 3;
	l1.b = 4;
	l1.str = "hello";

	Link l2;
	l2.a = 3;
	l2.b = 2;
	l2.str = "bye";

	Link l3;
	l3.a = 4;
	l3.b = 5;
	l3.str = "good";

	Link l4;
	l4.a = 4;
	l4.b = 5;
	l4.str = "good";

	vector<Link> linkSet;
	linkSet.push_back(l1);
	linkSet.push_back(l2);
	linkSet.push_back(l3);
	linkSet.push_back(l4);

	cout << "排序前："<<endl;
	//控制台输出
	for (int i = 0; i<linkSet.size(); i++)
	{
		cout << linkSet[i].a << " " << linkSet[i].b << " " << linkSet[i].str.c_str() << " " << endl;
	}

	//自定义删除
	auto cmp = [](Link x, Link y)
	{
			if (x.a == y.a)
				return x.b < y.b;
			return x.a < y.a;
	};
	sort (linkSet.begin(), linkSet.end(), cmp);

	cout << "排序后：" << endl;
	//控制台输出
	for (int i = 0; i<linkSet.size(); i++)
	{
		cout << linkSet[i].a << " " << linkSet[i].b << " " << linkSet[i].str.c_str() << " " << endl;
	}

	//自定义删除
	auto del= [](Link i, Link j)
	{	
		return i.a == j.a && i.b ==j.b;
	};
	std::vector<Link>::iterator last;
	last = unique(linkSet.begin(), linkSet.end(), del);
	linkSet.erase(last, linkSet.end());

	cout << "删除后：" << endl;
	//控制台输出
	for (int i = 0; i<linkSet.size(); i++)
	{
		cout << linkSet[i].a << " " << linkSet[i].b << " " << linkSet[i].str.c_str() << " " << endl;
	}
	system("pause");
	return 0;
}

运行结果如下图

• 重载运算符，输出结果如上图

#include<iostream>
#include<algorithm>
#include<cstring>
#include<vector>
using namespace std;
class Link
{
public:
	int a;
	int b;
	string str;
};

inline bool operator<(const Link& s1, const Link& s2)
{
	if (s1.a == s2.a)
		return s1.b < s2.b;
	return s1.a < s2.a;

}
inline bool operator==(const Link& s1, const Link& s2)
{
	return s1.a == s2.a && s1.b == s2.b;

}
int main()
{
	Link l1;
	l1.a = 3;
	l1.b = 4;
	l1.str = "hello";

	Link l2;
	l2.a = 3;
	l2.b = 2;
	l2.str = "bye";

	Link l3;
	l3.a = 4;
	l3.b = 5;
	l3.str = "good";

	Link l4;
	l4.a = 4;
	l4.b = 5;
	l4.str = "good";

	vector<Link> linkSet;
	linkSet.push_back(l1);
	linkSet.push_back(l2);
	linkSet.push_back(l3);
	linkSet.push_back(l4);

	cout << "排序前：" << endl;
	//控制台输出
	for (int i = 0; i < linkSet.size(); i++)
	{
		cout << linkSet[i].a << " " << linkSet[i].b << " " << linkSet[i].str.c_str() << " " << endl;
	}
	//自定义
	auto cmp = [](Link x, Link y)
	{
		if (x.a == y.a)
			return x.b < y.b;
		return x.a < y.a;
	};
	sort(linkSet.begin(), linkSet.end());

	cout << "排序后：" << endl;
	//控制台输出
	for (int i = 0; i < linkSet.size(); i++)
	{
		cout << linkSet[i].a << " " << linkSet[i].b << " " << linkSet[i].str.c_str() << " " << endl;
	}
	//自定义删除
	auto mycompare = [](Link i, Link j)
	{
		return i.a == j.a && i.b == j.b;
	};
	std::vector<Link>::iterator last;

	last = unique(linkSet.begin(), linkSet.end());
	linkSet.erase(last, linkSet.end());

	cout << "删除后：" << endl;
	//控制台输出
	for (int i = 0; i < linkSet.size(); i++)
	{
		cout << linkSet[i].a << " " << linkSet[i].b << " " << linkSet[i].str.c_str() << " " << endl;
	}
	system("pause");
	return 0;
}