Fonction ajouter une personne dans une liste chainné

Bonjour, Svp je comprend pas le role de la fonction vérification_ ide utilisée dans la fonction add(list*list)
void add(List *list)
{
int test=0,i;
do
{
int id;
Person new_person;
Element * new_element=(Element*) malloc(sizeof(Element));
printf("Enter your last name :\n");
scanf("%s",new_person.last_name);
printf("Enter your first name :\n");
scanf("%s",new_person.first_name);
printf("choose your gender (0)Man (1)Women :\n");
scanf("%u",&new_person.gender);
if (list->first==NULL) id=1;
else
id=list->first->person.usercode+1;
new_person.usercode=id;
printf("Your birthday:\n");
for (i = 0; i < 3; ++i)
{
switch(i)
{
case 0:
{
printf("Enter the day :\n");
break;
}
case 1:
{
printf("Enter the month :\n");
break;
}
case 2:
{
printf("Enter the year :\n");
break;
}
}
scanf("%d",&new_person.birthday[i]);
}
printf("enter your CIN :\n");
scanf("%s",new_person.CIN);
new_person.usercode=id;
printf("enter the number of children :\n");
scanf("%u",&new_person.nbr_children);
if (new_person.nbr_children!=0)
{
printf("Enter the id of the children :\n");
}
for (i = 0;i < new_person.nbr_children; i++)
{
scanf("%d",&id);
if (verification_ide(list,id,new_person.gender)==1)
{
new_person.child_id[i]=id;

}
else
i--;
}
new_element->person=new_person;
new_element->next=list->first;
list->first=new_element;

printf("if you want to add a new person press on (1) :\n");
scanf("%d",&test);
} while (test==1);
}


int verification_ide(List *list,int id,int gender)
{
int i;
Element *element=malloc(sizeof(Element));
element=list->first;
while((element!=NULL))
{
if(element->person.gender==gender)
{
for(i=0;i<element->person.nbr_children;i++)
{
if(id==element->person.child_id[i])
return 0;

}
}

element=element->next;
}

return 1;
}