c++STL之常用遍历算法

需要引入头文件#include<algorithm>

1.for_each

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

class MyPrint {
public:
    void operator()(int val) const{
        cout << val << " ";
    }    
};

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

void test() {
    vector<int> v1;
    for (int i = 0; i < 10; i++)
    {
        v1.push_back(i);
    }
    //利用普通函数
    for_each(v1.begin(), v1.end(), printVector);
    cout << endl;
    //利用仿函数
    for_each(v1.begin(), v1.end(), MyPrint());
    cout << endl;
}


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

2.transform：将容器搬运到另一个容器中

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

class Transform {
public:
    int operator()(int val) const{
        //这里可以对val进行一些判断
        return val;
    }    
};
class MyPrint {
public:
    void operator()(int val) const {
        cout << val << " ";
    }
};

void test() {
    vector<int> v1;
    for (int i = 0; i < 10; i++)
    {
        v1.push_back(i);
    }
    vector<int> v2;
    //目标容器需要先开辟空间
    v2.resize(v1.size());
    transform(v1.begin(), v1.end(), v2.begin(), Transform());
    for_each(v2.begin(), v2.end(), MyPrint());
    cout << endl;
}


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