c++STL之常用拷贝和替换算法
copy：容器中指定元素拷贝到另一容器中
replace：将容器内指定范围内的旧元素改为新元素
replace_if：容器内指定范围为满足条件的元素替换为新元素
swap：互换两个容器的元素
1.copy
#include<iostream>
using namespace std;
#include <vector>
#include <algorithm>
//常用拷贝和替换算法 copy
void myPrint(int val)
{
cout << val << " ";
}
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());
for_each(v2.begin(), v2.end(), myPrint);
cout << endl;
}
int main() {
test01();
system("pause");
return 0;
}2.replace
#include<iostream>
using namespace std;
#include <vector>
#include<algorithm>
class MyPrint
{
public:
void operator()(int val)
{
cout << val << " ";
}
};
//常用拷贝和替换算法 replace
void test01()
{
vector<int>v;
v.push_back(20);
v.push_back(30);
v.push_back(50);
v.push_back(30);
v.push_back(40);
v.push_back(20);
v.push_back(10);
v.push_back(20);
cout << "替换前：" << endl;
for_each(v.begin(), v.end(), MyPrint());
cout << endl;
//将20 替换 2000
replace(v.begin(), v.end(), 20, 2000);
cout << "替换后：" << endl;
for_each(v.begin(), v.end(), MyPrint());
cout << endl;
}
int main() {
test01();
system("pause");
return 0;
}3.replace_if
#include<iostream>
using namespace std;
#include <vector>
#include <algorithm>
class MyPrint
{
public:
void operator()(int val)
{
cout << val << " ";
}
};
class Greater30
{
public:
bool operator()(int val)
{
return val >= 30;
}
};
//常用拷贝和替换算法 replace_if
void test01()
{
vector<int>v;
v.push_back(10);
v.push_back(40);
v.push_back(20);
v.push_back(40);
v.push_back(30);
v.push_back(50);
v.push_back(20);
v.push_back(30);
cout << "替换前： " << endl;
for_each(v.begin(), v.end(), MyPrint());
cout << endl;
//将大于等于30 替换为 3000
replace_if(v.begin(), v.end(), Greater30(),3000);
cout << "替换后： " << endl;
for_each(v.begin(), v.end(), MyPrint());
cout << endl;
}
int main() {
test01();
system("pause");
return 0;
}4.swap
#include<iostream>
using namespace std;
#include <vector>
#include <algorithm>
//常用拷贝和替换算法 swap
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+100);
}
cout << "交换前： " << endl;
for_each(v1.begin(), v1.end(), myPrint);
cout << endl;
for_each(v2.begin(), v2.end(), myPrint);
cout << endl;
cout << "-----------------" << endl;
cout << "交换后： " << endl;
swap(v1, v2);
for_each(v1.begin(), v1.end(), myPrint);
cout << endl;
for_each(v2.begin(), v2.end(), myPrint);
cout << endl;
}
int main() {
test01();
system("pause");
return 0;
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原始发表：2019-12-29 ，如有侵权请联系 cloudcommunity@tencent.com 删除
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