代码：

 

#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>struct Family *get_person(void);    /* Prototype for input function */
char related(struct Family *pmember1, struct Family *pmember2);
char set_ancestry(struct Family *pmember1, struct Family *pmember2);struct Date   
{int day;int month;int year;
};struct Family                      /* Family structure declaration   */
{struct Date dob;char name[20];char father[20];char mother[20];struct Family *next;            /* Pointer to next structure      */struct Family *previous;        /* Pointer to previous structure  */struct Family *p_to_pa;         /* Pointer to father structure   */struct Family *p_to_ma;         /* Pointer to mother structure   */
};void main()
{struct Family *first = NULL;    /* Pointer to first person        */struct Family *current = NULL;  /* Pointer