C++之常用的拷贝和替换算法

C++之常用的拷贝和替换算法

copy

#include<iostream>
using namespace std;
#include<vector>
#include<algorithm>

void Myptint(int val)
{
	cout << val << " ";
}

void test()
{
	vector<int> v;
	for (int i = 0; i < 10; i++)
	{
		v.push_back(i);
	}
	vector<int>v2;
	v2.resize(v.size());
	copy(v.begin(), v.end(), v2.begin());
	for_each(v2.begin(), v2.end(), Myptint);
	cout << endl;
}

int main()
{
	test();
	system("pause");
	return 0;
}

replace

#include<iostream>
using namespace std;
#include<vector>
#include<algorithm>

void Myptint(int val)
{
	cout << val << " ";
}

void test()
{
	vector<int> v;
	v.push_back(10);
	v.push_back(30);
	v.push_back(50);
	v.push_back(20);
	cout << "替换前" << endl;
	for_each(v.begin(), v.end(), Myptint);
	cout << endl;

	//将50替换为500
	replace(v.begin(), v.end(), 50, 500);
	cout << "替换后" << endl;
	for_each(v.begin(), v.end(), Myptint);
	cout << endl;

}

int main()
{
	test();
	system("pause");
	return 0;
}

replace_if

#include<iostream>
using namespace std;
#include<vector>
#include<algorithm>

void Myptint(int val)
{
	cout << val << " ";
}

class Greater30
{
public:
	bool operator()(int val)
	{
		return val >= 30;
	}
};

void test()
{
	vector<int> v;
	v.push_back(10);
	v.push_back(30);
	v.push_back(50);
	v.push_back(20);
	cout << "替换前" << endl;
	for_each(v.begin(), v.end(), Myptint);
	cout << endl;

	//将大于等于30替换为500
	replace_if(v.begin(), v.end(), Greater30(), 500);
	cout << "替换后" << endl;
	for_each(v.begin(), v.end(), Myptint);
	cout << endl;

}

int main()
{
	test();
	system("pause");
	return 0;
}

swap

#include<iostream>
using namespace std;
#include<vector>
#include<algorithm>

void Myptint(int val)
{
	cout << val << " ";
}


void test()
{
	vector<int> v;
	vector<int>v2;
	for (int i = 0; i < 10; i++)
	{
		v.push_back(i);
		v2.push_back(i + 10);
	}
	cout << "交换前" << endl;
	for_each(v.begin(), v.end(), Myptint);
	cout << endl;
	for_each(v2.begin(), v2.end(), Myptint);
	cout << endl;

	swap(v, v2);
	cout << "交换后" << endl;
	for_each(v.begin(), v.end(), Myptint);
	cout << endl;
	for_each(v2.begin(), v2.end(), Myptint);
	cout << endl;
}

int main()
{
	test();
	system("pause");
	return 0;
}