找出指针和结构

我一直在尝试弄清楚如何处理指针＆amp;结构。我写了以下代码。

#include <iostream>
using namespace std;
struct Person
{
    char name[20]; //Question 2
    int id;
};
const int max_num_of_childs=10;
struct Family
{
    Person dad;
    Person mom;
    int num_of_childs;
    Person* child[max_num_of_childs];
};
void add_child (Family& f)
{
    char answer;
    do
    {
        if (f.num_of_childs==max_num_of_childs)
        {
            cout << "no more children" <<endl;
            return;
        }
        cout << "more child? Y/N" <<endl;
        cin >> answer;
        if (answer == 'Y')
        {
            f.child[f.num_of_childs] = new Person;
            cout << "enter name and id" << endl;
            cin >> f.child[f.num_of_childs]->name;
            cin >> f.child[f.num_of_childs]->id;
            f.num_of_childs++;
        }
    }
    while (answer=='Y');
    return;
}
void add (Family& f)
{
    cout << "insert dad name & id" << endl;
    cin >> f.dad.name >> f.dad.id;
    cout << "ninsert mom name & id" << endl;
    cin >> f.mom.name >> f.mom.id;
    add_child (f);
}
void print_child (const Family f) //Question 1
{
    for (int i=0; i<f.num_of_childs; i++)
        cout << "#" << i+1 << "child name: " << f.child[f.num_of_childs]->name << "child id: " << f.child[f.num_of_childs]->id << endl;
}
void print (const Family f)
{
    cout << "dad name: " << f.dad.name << "tdad id: " << f.dad.id << endl;
    cout << "mom name: " << f.mom.name << "tmom id: " << f.mom.id << endl;
    print_child (f);
}
int main()
{
    Family f;
    f.num_of_childs=0;
    add(f);
    print(f);
    return 0;
}

为什么print_child() gibberish的输出？

爸爸名：AAAA爸爸ID：11妈妈名：BBBB妈妈ID：221个子名称：•Uï∞U U U U uh░├evhchildID：68460532个孩子的名称：•Uï∞U U U U Uh░├evhchildID：6846053

如何定义一个无限长度的字符阵列？(使用字符串还需要定义的长度(。