结构体数组问题。？！

这个第二题的for语句中该怎么填，请求指点下
123456789123456789123456789

供参考：

for (p = person; p < person + sizeof(person) / sizeof(person[0]); p++)
    {
        if (old < p->age)
        {
            q = p;
            old = q->age;
        }
    }
    printf("%s %d", q->name, q->age);

#include<stdio.h>
#include<string.h>
static struct man
{
    char name[20];
    int age;
}person[] = { { "li-ming", 18 }, {"wang-hua", 19}, {"zhang-ping", 20} }; 
main()
{
    struct man *p, *q='0';
    int old = 0;
    for (p=&person;p->age; p++)
        if (old < p->age)
        {
            q = p;
            old=p->age;
        }
    printf("%s %d", q->name,old);
}