C++常用遍历算法—for_each、transform
1、for_each—遍历容器
1.1 内置数据类型
void print1(int num)
{cout << "这个数字是：" << num << endl;
}void test1()
{vector<int> numList;for (int i = 0; i < 10; i++){numList.push_back(i);}for_each(numList.begin(), numList.end(), print1);
}
1.2 自定义数据类型
class Person
{
public:string name;int age;Person(string name, int age){this->name = name;this->age = age;}Person() {}
};void printPerson(Person &p)
{cout << p.name << "今年" << p.age << "岁了！" << endl;
}void test2()
{Person p1("ncs", 26);Person p2("nbl", 9);Person p3("zes", 51);vector<Person> pList;pList.push_back(p1);pList.push_back(p2);pList.push_back(p3);for_each(pList.begin(), pList.end(), printPerson);
}
2、transform—搬运一个容器的内容到另一个容器
2.1 自定义数据类型
int re(int num)
{return num + 10000;
}
void test3()
{vector<int> numList;for (int i = 0; i < 10; i++){numList.push_back(i);}vector<int>vTarget; for (int i = 0; i < 10; i++){vTarget.push_back(i);}for_each(vTarget.begin(), vTarget.end(), print1); vTarget.resize(vTarget.size() + numList.size()); transform(numList.begin(), numList.end(), vTarget.begin()+numList.size(), re);cout << "++++++++++++++++++++++\n";for_each(vTarget.begin(), vTarget.end(), print1);
}
2.2 自定义数据类型
Person ageAdd(Person& p)
{p.age = p.age + 30;return p;
}void test4()
{Person p1("ncs", 26);Person p2("nbl", 9);Person p3("zes", 51);vector<Person> pList;pList.push_back(p1);pList.push_back(p2);pList.push_back(p3);vector<Person> pList1;pList1.push_back(p1);pList1.push_back(p2);pList1.push_back(p3);for_each(pList.begin(), pList.end(), printPerson);pList.resize(pList.size() + pList1.size());transform(pList1.begin(), pList1.end(), pList.begin() + pList1.size(), ageAdd);cout << "++++++++++++++++++++++\n";for_each(pList.begin(), pList.end(), printPerson);}
