STL——常用排序算法

 1.sort()

void MyPrint(int val)
{
	cout << val << " ";
}
void test01()
{
	vector<int> v1;
	v1.push_back(10);
	v1.push_back(20);
	v1.push_back(40);
	v1.push_back(30);
	v1.push_back(20);
	v1.push_back(40);
	v1.push_back(50);
	sort(v1.begin(), v1.end(), greater<int>());//用内建函数模板实现降序
	for_each(v1.begin(), v1.end(), MyPrint);
	cout << endl;
}

2.random_shuffle()//随机打乱顺序

void MyPrint(int val)
{
	cout << val << " ";
}
void test01()
{
	vector<int> v1;
	srand((unsigned int)time(NULL));//随机数种子
	for (int i = 0; i < 10; i++)
	{
		v1.push_back(i);
	}
	for_each(v1.begin(), v1.end(), MyPrint);
	cout << endl;
	cout << "随机打乱顺序后" << endl;
	random_shuffle(v1.begin(), v1.end());//随机打乱顺序
	for_each(v1.begin(), v1.end(), MyPrint);
	cout << endl;
}

 3.merge()//归并

void MyPrint(int val)
{
	cout << val << " ";
}
void test01()
{
	vector<int> v1;
	vector<int> v2;
	for (int i = 0; i < 10; i++)
	{
		v1.push_back(i);
		v2.push_back(i + 1);
	}
	vector<int> v3;
	v3.resize(v1.size() + v2.size());//归并前必须先开辟空间
	merge(v1.begin(), v1.end(), v2.begin(), v2.end(), v3.begin());//必须是有序且升序
	for_each(v3.begin(), v3.end(), MyPrint);
	cout << endl;
}

4.reverse()//反转

void MyPrint(int val)
{
	cout << val << " ";
}
void test01()
{
	vector<int> v1;
	for (int i = 0; i < 10; i++)
	{
		v1.push_back(i);
	}
	cout << "反转前：" << endl;
	for_each(v1.begin(), v1.end(), MyPrint);
	cout << endl;
	reverse(v1.begin(), v1.end());//实现反转
	cout << "反转后：" << endl;
	for_each(v1.begin(), v1.end(), MyPrint);
	cout << endl;
}