16.STL-常用遍历算法

• 常用遍历算法

• for_each

• 用于遍历
• 有返回值
• 可以绑定参数进行输出

• transform

• 搬运
• 注意：目标容器要有容量

#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
using namespace std;
#include <vector>
#include <algorithm>
#include <functional>

class MyPrint
{
public:
	void operator()(int val)
	{
		cout << val << endl;
		m_Count++;
	}

	int m_Count = 0;
};

//for_each  用于遍历
//有返回值的
void test01()
{
	vector<int>v;
	for (int i = 0; i < 10;i++)
	{
		v.push_back(i);
	}

	MyPrint print = for_each(v.begin(), v.end(), MyPrint());

	cout << "print.count = " << print.m_Count << endl;

}

//for_each可以绑定参数输出
class MyPrint2 :public binary_function<int,int,void>
{
public:
	void operator()(int val , int start) const
	{
		cout << val << endl;
		
	}

};

void test02()
{
	vector<int>v;
	for (int i = 0; i < 10; i++)
	{
		v.push_back(i);
	}

	for_each(v.begin(), v.end(),  bind2nd( MyPrint2(), 1000));

}


//transform算法 将指定容器区间元素搬运到另一容器中
class MyTransform
{
public:
	int operator()(int val)
	{	
		return val + 10000;
	}
};
void test03()
{
	vector<int>v;
	for (int i = 0; i < 10; i++)
	{
		v.push_back(i);
	}



	vector<int>v2;
	v2.resize(v.size());

	transform(v.begin(), v.end(), v2.begin(), MyTransform());

	for_each(v2.begin(), v2.end(), [](int val){cout << val << " "; });

}

int main(){
	//test01();
	//test02();
	test03();


	system("pause");
	return EXIT_SUCCESS;
}