c++学习stl的一个分组案例

Question

//请问为啥没有输出结果

#include<iostream>
#include<vector>
#include<map>
#include<string>
#include<ctime>
#include<algorithm>
using namespace std;
class Print;
class Person
{
public:
    Person(int salary,string name);
    ~Person();

private:
    int m_Salary;
    string m_Name;

    friend void creatPerson(vector<Person>* v);
    friend void sortPerson(const vector<Person>& v, multimap<int, Person>* m); 
    friend class Print;
};

Person::Person(int salary,string name)
{
    m_Salary = salary;
    m_Name = name;
}

Person::~Person()
{
    
}

class Print
{
public:
    void operator()(const pair<int, Person>& p)
    {

        cout << "编号"<<p.first<<"\t工资" << p.second.m_Salary << "\t姓名" << p.second.m_Name << endl;
    }
};

void creatPerson(vector<Person>* v)
{
    char nameSeed[10] = { 'A','B','C','D','E','F','G','H','I','J'};
    for (int i = 0; i < 10; i++)
    {
        v->push_back(    Person (0, (const char*)nameSeed[i])        );
    }
}

void sortPerson(const vector<Person>& v, multimap<int, Person>* m)
{
    int id; 
    for (int i = 0; i < 10; i++)
    {
        id=rand() % 3 + 1;//1`3
        m->insert(make_pair(id, v[i]));        
    }
}




int main()
{
    vector<Person>v;
    creatPerson(&v);
    cout<<v.size()<<v.empty()  ;
    multimap<int, Person>m;
    sortPerson(v, &m);

    for_each(m.begin(),m.end(),Print());
    
}

Answer 1

51 行修改，要取 字符数组，不能取 字符转换，参考如下：

 
#include<iostream>
#include<vector>
#include<map>
#include<string>
#include<ctime>
#include<algorithm>
using namespace std;
class Print;
class Person
{
public:
    Person(int salary,string name);
    ~Person();
 
private:
    int m_Salary;
    string m_Name;
 
    friend void creatPerson(vector<Person>* v);
    friend void sortPerson(const vector<Person>& v, multimap<int, Person>* m); 
    friend class Print;
};
 
Person::Person(int salary,string name)
{
    m_Salary = salary;
    m_Name = name;
}
 
Person::~Person()
{
    
}
 
class Print
{
public:
    void operator()(const pair<int, Person>& p)
    {
 
        cout << "编号"<<p.first<<"\t工资" << p.second.m_Salary << "\t姓名" << p.second.m_Name << endl;
    }
};
 
void creatPerson(vector<Person>* v)
{
    char nameSeed[10] = { 'A','B','C','D','E','F','G','H','I','J'};
    for (int i = 0; i < 10; i++)
    {
        v->push_back(Person (0, (const char*)nameSeed)); // 修改
    }
}
 
void sortPerson(const vector<Person>& v, multimap<int, Person>* m)
{
    int id; 
    for (int i = 0; i < 10; i++)
    {
        id=rand() % 3 + 1;//1`3
        m->insert(make_pair(id, v[i]));        
    }
}
 
 
 
 
int main()
{
    vector<Person>v;
    creatPerson(&v);
    cout<<v.size()<<v.empty()  ;
    multimap<int, Person>m;
    sortPerson(v, &m);
 
    for_each(m.begin(),m.end(),Print());
    
}