STL---常用的拷贝和替换算法

常用的拷贝和替换算法

（1）copy(begin,end,targetbegin):一个容易拷贝到另一个容器中；目标容器需要预留空间；
copy(v.begin(),v1.end().ostream_iterator(cout," ")):将vector遍历打印到屏幕，相当与for_each;需要头文件iterator；
（2）replace(begin,end,val , updataval)：将容器中的所有val替换为updataval；
（3）repalce_if(begin,end,myCompare,updataval):将满足仿函数的数据，替换为updataval;
（4）swap(v1,v2):交换v1,v2的所有数据；

代码实践

#include<iostream>
#include<list>
#include<vector>
#include<algorithm>
#include<vector>
#include<iterator>
using namespace std;
//------------------------------------------------------------------------------------------------------------------------
//copy 
void test01()
{
	vector<int> v1;
	for(int i=0;i<10;i++)
	{
		v1.push_back(i);
	}
	vector<int> v2;
	v2.resize(v1.size());

	copy(v1.begin(),v1.end(),v2.begin());  //v1的内容拷贝到v2中
	copy(v2.begin(),v2.end(),ostream_iterator<int>(cout," "));//和for_each一样，需要加头文件#include<iterator>
	//for_each(v2.begin(),v2.end(),[](int val){cout<<val<<" ";});
	cout<<endl;
	//---------------------------------
	list<int> v1;
	for(int i=0;i<10;i++)
	{
		v1.push_back(i);
	}
	list<int> v2;
	v2.resize(v1.size());

	copy(v1.begin(),v1.end(),v2.begin());  //v1的内容拷贝到v2中
	copy(v2.begin(),v2.end(),ostream_iterator<int>(cout," "));//和for_each一样，需要加头文件#include<iterator>
	//for_each(v2.begin(),v2.end(),[](int val){cout<<val<<" ";});
	cout<<endl;
}
//------------------------------------------------------------------------------------------------------------------------
//replace  list可用
class myCompare
{
public:
	bool operator()(int val)
	{
		return val>5;
	}
};
void test02()
{
	list<int> l;
	for(int i=0;i<10;i++)
	{
		l.push_back(i);
	}
	l.push_back(4);
	l.push_back(4);
	l.push_back(4);
	l.push_back(4);

	replace(l.begin(),l.end(),4,400);
	copy(l.begin(),l.end(),ostream_iterator<int>(cout," "));
	cout<<endl;

	replace_if(l.begin(),l.end(),myCompare(),1000);
	copy(l.begin(),l.end(),ostream_iterator<int>(cout," "));
	cout<<endl;
}
//------------------------------------------------------------------------------------------------------------------------
//swap
void test03()
{
	list<int> l1;
	list<int> l2;
	for(int i=0;i<10;i++)
	{
		l1.push_back(i);
	}
	l2.push_back(10);
	l2.push_back(20);
	l2.push_back(30);
	l2.push_back(40);
	l2.push_back(50);
	l2.push_back(60);

	swap(l1,l2);
	copy(l1.begin(),l1.end(),ostream_iterator<int>(cout," "));
	cout<<endl;

	copy(l2.begin(),l2.end(),ostream_iterator<int>(cout," "));
	cout<<endl;



}
int main()
{
	//test03();
	//test02();
	test01();
	return 0;
}