Mega Code Archive
Basics of a family tree
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/*
Beginning C, Third Edition
By Ivor Horton
ISBN: 1-59059-253-0
Published: Apr 2004
Publisher: apress
*/
#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 to current person */
struct Family *last = NULL; /* Pointer to previous person */
char more = '\0'; /* Test value for ending input */
for( ; ; )
{
printf("\nDo you want to enter details of a%s person (Y or N)? ",
first != NULL?"nother " : "" );
scanf(" %c", &more);
if(tolower(more) == 'n')
break;
current = get_person();
if(first == NULL)
{
first = current; /* Set pointer to first Family */
last = current; /* Remember for next iteration */
}
else
{
last->next = current; /* Set next address for previous Family */
current->previous = last; /* Set previous address for current */
last = current; /* Remember for next iteration */
}
}
current = first;
while(current->next != NULL) /* Check for relation for each person in */
{ /* the list up to second to last */
int parents = 0; /* Declare parent count local to this block */
last = current->next; /* Get the pointer to the next */
while(last != NULL) /* This loop tests current person */
{ /* against all the remainder in the list */
if(related(current, last)) /* Found a parent ? */
if(++parents == 2) /* Yes, update count and check it */
break; /* Exit inner loop if both parents found */
last = last->next; /* Get the address of the next */
}
current = current->next; /* Next in the list to check */
}
/* Now tell them what we know */
/* Output Family data in correct order */
current = first;
while (current != NULL) /* Output Family data in correct order */
{
printf("\n%s was born %d/%d/%d, and has %s and %s as parents.",
current->name, current->dob.day, current->dob.month,
current->dob. year, current->father, current->mother);
if(current->p_to_pa != NULL )
printf("\n\t%s's birth date is %d/%d/%d ",
current->father, current->p_to_pa->dob.day,
current->p_to_pa->dob.month,
current->p_to_pa->dob.year);
if(current->p_to_ma != NULL)
printf("and %s's birth date is %d/%d/%d.\n ",
current->mother, current->p_to_ma->dob.day,
current->p_to_ma->dob.month,
current->p_to_ma->dob.year);
current = current->next; /* current points to next in list */
}
/* Now free the memory */
current = first;
while(current->next != NULL)
{
last = current; /* Save pointer to enable memory to be freed */
current = current->next; /* current points to next in list */
free(last); /* Free memory for last */
}
}
/* Function to input data on Family members */
struct Family *get_person(void)
{
struct Family *temp; /* Define temporary structure pointer */
/* Allocate memory for a structure */
temp = (struct Family*) malloc(sizeof(struct Family));
printf("\nEnter the name of the person: ");
scanf("%s", temp -> name ); /* Read the Family's name */
printf("\nEnter %s's date of birth (day month year); ", temp->name);
scanf("%d %d %d", &temp->dob.day, &temp->dob.month, &temp->dob.year);
printf("\nWho is %s's father? ", temp->name );
scanf("%s", temp->father ); /* Get the father's name */
printf("\nWho is %s's mother? ", temp -> name );
scanf("%s", temp -> mother ); /* Get the mother's name */
temp->next = temp->previous = NULL; /* Set pointers to NULL */
temp->p_to_pa = temp->p_to_ma = NULL; /* Set pointers to NULL */
return temp; /* Return address of Family structure */
}
char set_ancestry(struct Family *pmember1, struct Family *pmember2)
{
if(strcmp(pmember1->father, pmember2->name) == 0)
{
pmember1->p_to_pa = pmember2;
return 1;
}
if( strcmp(pmember1->mother, pmember2->name) == 0)
{
pmember1->p_to_ma = pmember2;
return 1;
}
else
return 0;
}
/* Fill in pointers for mother or father relationships */
char related (struct Family *pmember1, struct Family *pmember2)
{
return set_ancestry(pmember1, pmember2) ||
set_ancestry(pmember2, pmember1);
}
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